Converted more documentation pages

Modified the site CSS

docs/Messaging/_index.md

@@ -0,0 +1,4 @@
+---
+title: "Messaging"
+weight: 100
+---

docs/Messaging/message-broker.md

@@ -1,78 +1,146 @@
-Message Broker
+---
+title: "message_broker"
+---
 
-A variant of the observer pattern in that message routers and derived types are be able to subscribe to selected sets of messages. The message_broker is similar to the message_bus, but it provides more control over the routing of messages. While the message_bus simply broadcasts every message to all subscribers, the message_broker allows you to specify which subscribers should receive each message.
+{{< callout type="info">}}
+  Header: `message_broker.h`  
+{{< /callout >}}
 
-Derived from imessage_router
-____________________________________________________________________________________________________
-Types
+Message Broker  
 
+A variant of the observer pattern in that message routers and derived types are be able to subscribe to selected sets of messages. The message_broker is similar to the message_bus, but it provides more control over the routing of messages.  While the message_bus simply broadcasts every message to all subscribers, the message_broker allows you to specify which subscribers should receive each message.  
+
+Derived from `imessage_router`.
+
+## Types
+
+```cpp
 message_id_span_t    etl::span<const etl::message_id_t>
-____________________________________________________________________________________________________
-subscription
-A nested class of etl::message_broker
-The base for broker subscription information. 
-Derive from this to define your subscription class.
-See Example.
-____________________________________________________________________________________________________
-subscription(etl::imessage_router& router)
-Constructor.
-____________________________________________________________________________________________________
-virtual message_id_span_t message_id_list() const = 0;
-Override this to return a span of message ids.
-____________________________________________________________________________________________________
-message_broker
+```
 
+## subscription
+A nested class of `etl::message_broker`.
+The base for broker subscription information.  
+Derive from this to define your subscription class.  
+See Example.
+
+---
+
+```cpp
+subscription(etl::imessage_router& router)
+```
+Constructor.
+
+---
+
+```cpp
+virtual message_id_span_t message_id_list() const = 0;
+```
+Override this to return a span of message ids.
+
+## message_broker
+
+```cpp
 message_broker()
-The broker is constructed with an id of etl::imessage_router::MESSAGE_BROKER.
-____________________________________________________________________________________________________
+```
+The broker is constructed with an id of `etl::imessage_router::MESSAGE_BROKER`.
+
+---
+
+```cpp
 message_broker(etl::imessage_router& successor)
-The broker is constructed with an id of etl::imessage_router::MESSAGE_BROKER.
+```
+The broker is constructed with an id of `etl::imessage_router::MESSAGE_BROKER`.  
 Sets the successor.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 message_broker(etl::message_router_id_t id)
+```
 The broker is constructed with the specified id.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 message_broker(etl::message_router_id_t id, etl::imessage_router& successor)
-The broker is constructed with the specified id.
+```
+The broker is constructed with the specified id.  
 Sets the successor.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 void subscribe(etl::imessage_router& router)
-Subscribes an etl::imessage_router derived class to the broker.
-A subscription object must have a lifetime of at least the same as the broker.
+```
+Subscribes an `etl::imessage_router` derived class to the broker.  
+A subscription object must have a lifetime of at least the same as the broker.  
 A subscription cannot be shared with another broker.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 void unsubscribe(etl::imessage_router& router)
-Unsubscribes the specified etl::imessage_router derived class from the bus.
+```
+Unsubscribes the specified `etl::imessage_router` derived class from the bus.  
 Does not unsubscribe from nested buses.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 void receive(const etl::imessage& message)
 void receive(etl::shared_message message)
-Receives a message and distributes it to all subscribers that have registered to receive the message type.
-Forwards the message to any successor.
+```
+Receives a message and distributes it to all subscribers that have registered to receive the message type.  
+Forwards the message to any successor.  
 
-Override this in a derived class if you wish to capture messages sent to the broker.
+Override this in a derived class if you wish to capture messages sent to the broker.  
 Call the base receive function from here to allow normal operation to continue.
-____________________________________________________________________________________________________
-bool accepts(etl::message_id_t id) const
-Always returns true.
-____________________________________________________________________________________________________
-void clear()
-Clears the broker of all subscribers.
-____________________________________________________________________________________________________
-ETL_DEPRECATED bool is_null_router() const ETL_OVERRIDE
-Always returns false.
-____________________________________________________________________________________________________
-bool is_producer() const ETL_OVERRIDE
-Always returns true.
-____________________________________________________________________________________________________
-bool is_consumer() const ETL_OVERRIDE
-Always returns true.
-____________________________________________________________________________________________________
-bool empty() const
-Returns true is the are are no subscribers.
-____________________________________________________________________________________________________
-Example
 
+---
+
+```cpp
+bool accepts(etl::message_id_t id) const
+```
+Always returns `true`.
+
+---
+
+```cpp
+void clear()
+```
+Clears the broker of all subscribers.
+
+---
+
+```cpp
+ETL_DEPRECATED bool is_null_router() const ETL_OVERRIDE
+```
+Always returns `false`.
+
+---
+
+```cpp
+bool is_producer() const ETL_OVERRIDE
+```
+Always returns `true`.
+
+---
+
+```cpp
+bool is_consumer() const ETL_OVERRIDE
+```
+Always returns `true`.
+
+---
+
+```cpp
+bool empty() const
+```
+Returns `true` is the are are no subscribers.
+
+## Example
+```cpp
 // Some router ids.
 enum
 {
@@ -145,4 +213,4 @@ broker.receive(message1); // Received by router1
 broker.receive(message2); // Received by router1 and router2
 broker.receive(message3); // Received by router2
 broker.receive(message4); // Received by router2 as a Message3
-
+```

docs/Messaging/message-bus.md

@@ -0,0 +1,206 @@
+---
+title: "message_bus"
+---
+
+{{< callout type="info">}}
+  Header: `message_broker.h`  
+  Since: `20.33.0`
+{{< /callout >}}
+
+Message Bus  
+
+This page documents version `20.0.0` and above.  
+
+A variant of the observer pattern in that message routers and derived types are be able to subscribe to messages on a bus. The messages can be either broadcast, to be automatically picked up by any router that has a handler, or addressed to a particular router or router id. Message buses may be nested  by setting a successor.  
+
+## imessage_bus
+Derived from imessage_router.  
+
+The base for all message buses.  
+Inherits publicly from `etl::imessage_router`.  
+Message buses are therefore also a type of  router.  
+Objects of type `etl::imessage_bus` cannot be directly constructed.  
+
+## Member functions
+
+```cpp
+bool subscribe(etl::imessage_router& router)
+```
+Subscribes an `etl::imessage_router` derived class to the bus.  
+Returns `true` on success.
+
+---
+
+```cpp
+void unsubscribe(etl::imessage_router& router)
+```
+Unsubscribes the specified `etl::imessage_router` derived class from the bus.  
+Does not unsubscribe from nested buses.
+
+---
+
+```cpp
+void unsubscribe(etl::message_router_id_t id)
+```
+Unsubscribes routers with the specified id from the bus.  
+Does not unsubscribe from nested buses.  
+
+`etl::imessage::MESSAGE_BUS` will unsubscribe all message buses.  
+`etl::imessage::ALL_MESSAGE_ROUTERS` will unsubscribe all routers and buses. Equivalent to calling `clear()`.
+
+---
+
+```cpp
+void receive(const etl::imessage& message)
+void receive(etl::shared_message message)
+```
+Receives a message and distributes it to all subscribers.  
+Forwards the message to any successor.  
+
+The routers are called first, in order of ascending router id.  
+Routers with the duplicate ids will be called in subscribe order.  
+Any nested message buses are called in subscribe order.
+
+---
+
+```cpp
+void receive(etl::message_router_id_t destination_router_id, 
+             const etl::imessage&     message);
+void receive(etl::message_router_id_t destination_router_id, 
+             etl::shared_message message)
+```
+Receives a message and distributes it to all subscribers that have the specified router id.  
+Forwards the message to any successor.  
+
+Routers with the duplicate ids will be called in subscribe order.  
+Any nested message buses are called in subscribe order.  
+
+Override this in a derived class if you wish to capture messages sent to the bus.  
+Call the base receive function from here to allow normal operation to continue.
+
+---
+
+```cpp
+bool accepts(etl::message_id_t id) const
+```
+Always returns `true`.
+
+---
+
+```cpp
+size_t size() const
+```
+Returns the number of subscribers.
+
+---
+
+```cpp
+void clear()
+```
+Clears the bus of all subscribers.  
+
+Message buses inherit all of the public functions of `etl::imessage_router`.
+
+## Errors
+
+```cpp
+message_bus_exception
+```
+Base error class for `etl::message_bus`. Inherits from `etl::exception`.
+
+---
+
+```cpp
+message_bus_too_many_subscribers
+```
+Emitted when the number of subscribers exceeds the capacity. Inherits from `etl::message_bus_exception`.
+
+## message_bus
+Derived from `imessage_bus`.
+
+```cpp
+template <const uint_least8_t MAX_ROUTERS>
+class message_bus
+```
+`MAX_ROUTERS` The maximum number of routers that can be subscribed.
+
+## Member functions
+
+```cpp
+message_bus()
+```
+Constructs a message bus.  
+Message buses always have a router id of `etl::imessage::MESSAGE_BUS`.
+
+```cpp
+message_bus(etl::imessage_router& successor)
+```
+Constructs a message bus and sets the successor.  
+Message buses always have a router id of `etl::imessage::MESSAGE_BUS`.
+
+## Example
+```cpp
+// Some router ids.
+enum
+{
+  ROUTER_ID_1,
+  ROUTER_ID_2,
+  ROUTER_ID_3
+};
+
+// Instances of messages.
+MessageA messageA;
+
+// Instances of message routers.
+RouterA routerA(ROUTER_ID_1);
+RouterB routerB(ROUTER_ID_1);
+RouterC routerC(ROUTER_ID_2);
+RouterD routerD(ROUTER_ID_3);
+RouterE routerE(ROUTER_ID_1);
+
+// Instances of message buses.
+etl::message_bus<4> bus1;
+etl::message_bus<2> bus2;
+etl::message_bus<1> bus3;
+
+// Subscribe bus2 & bus3 to bus1.
+bus1.subscribe(bus3);
+bus1.subscribe(bus2);
+
+// Subscribe routerB & routerA to bus1.
+bus1.subscribe(routerB);
+bus1.subscribe(routerA);
+
+// Subscribe routerD & routerC to bus2.
+bus2.subscribe(routerD);
+bus2.subscribe(routerC);
+
+// Subscribe routerE to bus3.
+bus3.subscibe(routerE);
+
+// Assume all routers accept the same messages.
+
+// Broadcast messageA to everyone.
+bus1.receive(messageA);
+
+// The call order will be...
+// routerB
+// routerA
+// routerE
+// routerC
+// routerD
+
+// Address messageA to routers with id ROUTER_ID_1.
+bus1.receive(ROUTER_ID_1, messageA);
+
+// The call order will be...
+// routerB
+// routerA
+// routerE
+
+// Address messageA to routers with id ROUTER_ID_3.
+bus1.receive(ROUTER_ID_3, messageA);
+```
+// The call order will be...
+// routerD
+```

docs/Messaging/message-packet.md

@@ -0,0 +1,155 @@
+---
+title: "message_packet"
+---
+
+{{< callout type="info">}}
+  Header: `message_packet.h`  
+{{< /callout >}}
+
+A container for more than one type of message.  
+The messages must have been derived from `etl::imessage`.
+
+The messages types that the packet may contain are listed as template parameters.  
+e.g. `etl::message_packet<Message1, Message2, Message3>`  
+
+From `20.40.0` message types are not required to have a virtual destructor.
+
+---
+
+```cpp
+message_packet()
+```
+Default constructs a message packet.  
+`is_valid()` returns `false`.
+
+---
+
+```cpp
+explicit message_packet(const etl::imessage&)
+```
+Constructs a message packet from an `etl::imessage` reference.  
+Asserts an `etl::unhandled_message_exception` error if the parameter is not one listed in the template parameter list.  
+
+---
+
+```cpp
+explicit message_packet(etl::imessage&&) C++11
+```
+Move constructs a message packet from an `etl::imessage` rvalue reference.  
+Emits an `etl::unhandled_message_exception` error if the parameter is not one listed in the template parameter list.
+
+---
+
+```cpp
+template <typename TMessage>
+explicit message_packet(const TMessage&)
+```
+Constructs a message packet from a `TMessage` reference.
+Emits a compile time static assert if the parameter is not one listed in the template parameter list.  
+Since: `20.22.0`
+
+---
+
+```cpp
+template <typename TMessage>
+explicit message_packet(TMessage&&)
+```
+Move constructs a message packet from a `TMessage` rvalue reference.
+Emits a compile time static assert if the parameter is not one listed in the template parameter list.  
+Since: `20.22.0`
+
+---
+
+```cpp
+message_packet(const message_packet&)
+```
+Constructs a message packet from an `message_packet` reference.  
+Emits an `etl::unhandled_message_exception` error if the parameter is not one listed in the template parameter list.
+
+---
+
+```cpp
+message_packet(message_packet&&)
+```
+Move constructs a message packet from an `message_packet` rvalue reference.  
+Emits an `etl::unhandled_message_exception` if the parameter is not one listed in the template parameter list.
+
+---
+
+```cpp
+message_packet& operator =(const message_packet&)
+```
+Assigns a message packet from an `message_packet` reference.  
+Emits an `etl::unhandled_message_exception` error if the parameter is not one listed in the template parameter list.
+
+---
+
+```cpp
+message_packet& operator =(message_packet&&)
+```
+Move assigns a message packet from an `message_packet` rvalue reference.  
+Emits an `etl::unhandled_message_exception` error if the parameter is not one listed in the template parameter list.
+
+---
+
+```cpp
+etl::imessage& get()
+const etl::imessage& get() const
+```
+Returns a reference to an `etl::imessage`.
+
+---
+
+```cpp
+bool is_valid() const
+```
+Returns `true` if the packet contains a valid message, otherwise `false`.
+
+---
+
+## Constants
+
+`SIZE`      The size of the largest message.
+`ALIGNMENT` The largest message alignment.
+
+---
+
+## Example
+```cpp
+enum
+{
+  MESSAGE1,
+  MESSAGE2,
+  MESSAGE3
+};
+
+struct Message1 : public etl::message<MESSAGE1>
+{
+};
+
+struct Message2 : public etl::message<MESSAGE2>
+{
+};
+
+struct Message3 : public etl::message<MESSAGE3>
+{
+};
+
+using Packet = etl::message_packet<Message1, Message2>
+
+Message1 message1;
+Message2 message2;
+Message3 message3;
+
+Packet packet1(message1);
+Packet packet2(message2);
+Packet packet3(message3); // Runtime time error! Packet does not support Message3 type.
+
+etl::imessage& m1 = message1;
+Packet packet4(m1); // Construct from an etl::imessage reference.
+
+etl::imessage& m3 = message3;
+Packet packet4(m3); // Asserts etl::unhandled_message_exception! Packet does not support Message3 type.
+
+etl::imessage& m = packet2.get(); // Get a reference to an etl::imessage from the packet.
+```

docs/Messaging/messages.md

@@ -0,0 +1,111 @@
+---
+title: "Messages"
+---
+
+{{< callout type="info">}}
+  Header: `message.h`  
+{{< /callout >}}
+
+Message types used for many of the framework classes.
+
+---
+
+```cpp
+etl::message_id_t
+```
+The type used for message ids.  
+By default can hold a value between 0 and 255.  
+If `ETL_MESSAGE_ID_TYPE` is defined then this type will be used instead.
+
+---
+
+```cpp
+etl::message_router_id_t
+```
+The type used for message router ids.  
+Can hold a value between 0 and 255.
+
+---
+
+The message classes are the common communication method across all of the message capable frameworks.
+They are identified by a unique id number that specialises the base class.
+
+## imessage
+
+The base class for messages. 
+It is this class that is passed around, usually by const reference.  
+The class is abstract.  
+
+---
+
+```cpp
+etl::message_id_t get_message_id() const ETL_NOEXCEPT = 0;
+```
+Returns the id of the message.
+
+---
+
+## message
+
+```cpp
+message<size_t ID, typename TParent = etl::imessage>
+```
+Requires an integral id as the template parameter.  
+Inherits from `TParent`, which defaults to `etl::imessage`.  
+`TParent` allows additional base interfaces or  functionality to be included.  
+static asserts if `TParent` is not a base of `etl::imessage`.
+
+---
+
+```cpp
+ID
+```
+The id of the message as an enum.
+Can be accessed by `etl::message` instances.
+
+---
+
+```cpp
+TParent
+```
+The class that it inherits from. It must ultimately derive from `etl::imessage`.  
+The default is `etl::imessage`.
+
+---
+
+## Example
+
+```cpp
+enum
+{
+  START,
+  STOP,
+  SET_SPEED
+};
+
+struct MyInterface : public etl::imessage
+{
+  virtual void DoStuff() = 0;
+};
+
+// Start implements MyIterface
+struct Start : public etl::message<START, MyInterface>
+{
+  void DoStuff() override
+  {
+    // Do stuff here.  
+  }
+};
+
+struct Stop : public etl::message<STOP>
+{
+  bool isEmergencyStop;
+};
+
+struct SetSpeed : public etl::message<SET_SPEED>
+{
+  uint32_t speed;
+};
+
+void Receive(const etl::imessage& msg);
+```

docs/Messaging/shared-message.md

@@ -0,0 +1,78 @@
+---
+title: "shared_message"
+---
+
+{{< callout type="info">}}
+  Header: `shared_message.h`  
+{{< /callout >}}
+
+Shared Messages  
+
+The type used to encapsulate reference counted messages.  
+Shared messages are usually passed by value.  
+
+See the Shared Message Tutorial  
+
+---
+
+```cpp
+template <typename TPool, typename TMessage>
+shared_message(TPool& owner, const TMessage& message)
+```
+Static asserts if `TPool` is not derived from `etl::ireference_counted_message_pool`
+Static asserts if `TMessage` not derived from `etl::imessage`.  
+
+Requires that `TPool` implements the following member function to allocate from the pool.  
+
+```cpp
+template <typename TMessage>
+etl::ireference_counted_message* allocate(const TMessage& message)
+```
+---
+
+```cpp
+explicit shared_message(etl::ireference_coutnted_message& message)
+```
+Construct from a reference counted message.
+
+---
+
+```cpp
+shared_message(const etl::shared_message& other)
+```
+Copy constructor.
+
+---
+
+```cpp
+shared_message& operator =(const etl::shared_message& other)
+```
+Assignment operator.
+
+---
+
+```cpp
+~shared_message()
+```
+Destructor.
+
+---
+
+```cpp
+ETL_NODISCARD etl::imessage& get_message()
+```
+Gets a reference to the contained message.
+
+---
+
+```cpp
+ETL_NODISCARD const etl::imessage& get_message() const
+```
+Gets a const reference to the contained message.
+
+---
+
+```cpp
+ETL_NODISCARD uint32_t get_reference_count() const
+```
+Gets the current reference count for this shared message.

docs/frameworks/_index.md

@@ -0,0 +1,4 @@
+---
+title: "Frameworks"
+weight: 100
+---

docs/frameworks/callback-service.md

@@ -1,57 +1,80 @@
-Callback Service
-This template class allows easier integration of 'C' style events (such as interrupt vectors) and C++ handlers.
-It can allow abstraction between low level events such as interrupts and their application dependent handlers.
-The handlers may be any combination of global, static or member functions. 
-It utilises the templated function wrapper. See here.
+---
+title: "callback_service"
+---
 
-The callbacks are identified by an id. The values of the ids must range from zero or a specified offset, up to the maximum number of specified callbacks. Calling an unused callback id will either do nothing or, if the user has specified a handler, call this with the id of the callback.
+{{< callout type="info">}}
+  Header: `callback_service.h`  
+{{< /callout >}}
 
-There are functions that use both runtime and compile time checks of the callback id. 
-Compile time is preferable.
-____________________________________________________________________________________________________
-Member functions
+This template class allows easier integration of 'C' style events (such as interrupt vectors) and C++ handlers.  
+It can allow abstraction between low level events such as interrupts and their application dependent handlers.  
+The handlers may be any combination of global, static or member functions.  
+It utilises the templated function wrapper.  
 
+The callbacks are identified by an id. The values of the ids must range from zero or a specified offset, up to the maximum number of specified callbacks. Calling an unused callback id will either do nothing or, if the user has specified a handler, call this with the id of the callback.  
+
+There are functions that use both runtime and compile time checks of the callback id.  
+Compile time is preferable.  
+
+## Member functions
+
+```cpp
 template <const size_t RANGE, const size_t OFFSET = 0U>
 etl::callback_service
+```
+`RANGE`  The id range of the callbacks.
+`OFFSET` The starting id for the range.
 
-RANGE  The id range of the callbacks.
-OFFSET The starting id for the range.
-____________________________________________________________________________________________________
+It can allow abstraction between low level events such as interrupts and their application dependent handlers.
+
+```cpp
 callback_service()
-
-Sets all of the callbacks to route to the unhandled callback.
+```
+Sets all of the callbacks to route to the unhandled callback.  
 Sets the unhandled callback to default (do nothing).
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 template <const size_t ID>
 void register_callback(etl::ifunction<size_t>& callback)
-
-Registers callback with the id specified in the template parameter.
+```
+Registers callback with the id specified in the template parameter.  
 A compile time error will occur if the id is out of range.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 void register_callback(size_t id, etl::ifunction<size_t>& callback)
-
-Registers callback with the id specified in the template parameter.
+```
+Registers callback with the id specified in the template parameter.  
 The registration will be ignored if the id is out of range.
-____________________________________________________________________________________________________
-void register_unhandled_callback(etl::ifunction<size_t>& callback)
 
+---
+
+```cpp
+void register_unhandled_callback(etl::ifunction<size_t>& callback)
+```
 Registers the callback to be used for unhandled ids.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 template <const size_t ID>
 void callback()
-
-Calls the callback associated with the id. 
-Calls the unhandled callback if the id has not been registered.
+```
+Calls the callback associated with the id.  
+Calls the unhandled callback if the id has not been registered.  
 A compile time error will occur if the id is out of range.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 void callback(const size_t id)
-
-Calls the callback associated with the id. 
+```
+Calls the callback associated with the id.  
 Calls the unhandled callback if the id has not been registered or if is out of range.
-____________________________________________________________________________________________________
-Example
 
-Tutorial
-
-See the example project in etl\examples\FunctionInterruptSimulation
+## Example
 
+See the example project in `examples\FunctionInterruptSimulation`.

docs/frameworks/cooperative-scheduler.md

@@ -0,0 +1,211 @@
+---
+title: "scheduler"
+---
+
+{{< callout type="info">}}
+  Header: `scheduler.h`  
+{{< /callout >}}
+
+A lightweight cooperative multi-tasking scheduler.  
+Can be used stand-alone or in conjunction with a messaging system such as the ETL's message router or FSM as the back-end handler. For use when a complex OS or RTOS is overkill.  
+
+Calls an 'idle' callback whenever the scheduler returns `true`.  
+Calls a 'watchdog' callback whenever the scheduler returns.  
+
+The scheduler makes use of `etl::task`.
+
+## Scheduling Policies
+A number of built-in scheduling policies are available.
+Note: The tasks are stored in decreasing priority id order. i.e. Higher id = higher priority.
+
+### Sequential Single
+```cpp
+etl::scheduler_policy_sequential_single
+```
+A sequential algorithm that calls a task if it has work to do , starting from the highest priority task.  
+On return, it moves to the next task in the list. At the end of the list it returns the idle status.  
+If no tasks with work were found then the idle status is set to `true`.  
+
+### Sequential Multiple
+```cpp
+etl::scheduler_policy_sequential_multiple
+```
+A sequential algorithm that calls a task if it has work to do , starting from the highest priority task.  
+On return, it calls the task again if it still has work, otherwise it moves to the next task in the list.  
+At the end of the list it returns the idle status.  
+If no tasks with work were found then the idle status is set to `true`.  
+
+### Highest Priority
+```cpp
+etl::scheduler_policy_highest_priority
+```
+An algorithm that calls the highest priority task that has work to do.  
+Returns the idle status.  
+If no tasks with work were found then the idle status is set to `true`.  
+
+
+### Most Work
+```cpp
+etl::scheduler_policy_most_work
+```
+An algorithm that calls the task that has the most work to do, starting from the highest priority task.  
+Returns the idle status.  
+If no tasks with work were found then the idle status is set to `true`.  
+
+### Custom Scheduler
+Creating a custom scheduler policy is simple.  
+Just create a structure with the following signature and add your own scheduling algorithm.  
+To get 'idle' callbacks then the policy must regularly return `true`.  
+To get 'watchdog' callbacks then the policy must regularly return.  
+```cpp
+struct scheduler_policy_custom
+{
+  bool schedule_tasks(etl::ivector<etl::task*>& task_list)
+  {
+    bool idle = true;
+
+    //**************************************
+    // Add your scheduling policy here.
+    // Set 'idle' to false if any tasks were run.
+    //**************************************
+
+    return idle;
+  }
+};
+```
+
+## ischeduler
+Can be used as a reference to all scheduler instances.
+```cpp
+ischeduler()
+```
+Constructor
+
+```cpp
+void set_idle_callback(etl::ifunction<void>& callback)
+```
+Sets the function to be called when idle.
+
+---
+
+```cpp
+void set_watchdog_callback(etl::ifunction<void>& callback)
+```
+Sets the function to be called to reset the watchdog.
+
+---
+
+```cpp
+void set_scheduler_running(bool scheduler_running)
+```
+Sets the running state of the scheduler.
+
+---
+
+```cpp
+bool scheduler_is_running() const;
+```
+Gets the running state of the scheduler.
+
+---
+
+```cpp
+void exit_scheduler()
+```
+Instructs the scheduler to exit after the next idle call.
+
+---
+
+```cpp
+void add_task(etl::task& task)
+```
+Adds a task to the task list.  
+The task list is in priority order where higher id = higher priority. Tasks with duplicate ids are in insert order.  
+Emits an `etl::scheduler_too_many_tasks_exception` if the task list is full.  
+
+---
+
+```cpp
+template <typename TSize>
+void add_task_list(etl::task** p_tasks, TSize size);
+```
+Emits an `etl::scheduler_too_many_tasks_exception` if the task list is full.  
+Emits an `etl::scheduler_null_task_exception` if any of the task pointers is null.
+
+---
+
+```cpp
+virtual void start()
+```
+Starts the scheduler.
+
+## scheduler
+Inherits from `etl::ischeduler`.
+
+```cpp
+template <typename TSchedulerPolicy, size_t MAX_TASKS_>
+class scheduler
+```
+`TSchedulerPolicy` The policy to use schedule tasks.
+`MAX_TASKS`        The maximum number of tasks to schedule.
+
+---
+
+```cpp
+scheduler()
+```
+Constructor.
+
+---
+
+```cpp
+void start()
+```
+Starts the scheduler.  
+Emits an `etl::scheduler_no_tasks_exception` if there are no tasks in the list.
+
+## Errors
+
+```cpp
+scheduler_exception
+```
+Inherits from `etl::exception`
+
+---
+
+```cpp
+scheduler_no_tasks_exception
+```
+Inherits from `etl::scheduler_exception`
+
+---
+
+```cpp
+scheduler_null_task_exception
+```
+Inherits from `etl::scheduler_exception`
+
+## Overview of use
+As a basic example, you will have to define the following...
+
+**Tasks**  
+For each of your tasks, derive a class from etl::task and overide the two virtual functions uint32_t task_request_work() const and void task_process_work(). task_request_work returns a value that informs the scheduler that this task has work to process. The return value should be non-zero if the task has work. This meaning of this is user defined, it could be the number of messages in the task's queue, or just a 0 = no work, 1 = have work. task_process_work allows the task to process any work that it has. How much work it processes on each call is user defined; often it will be one 'unit' of work and letting the policy determine which task gets the next opportunity to process more.  
+
+**Task list**  
+An array of pointers to the tasks. Passed to the scheduler with `add_task_list`.  
+Use add_task to add additional tasks.
+
+**The scheduler**  
+An instance of `etl::scheduler` with the required scheduling policy.  
+Initialise the task list by calling add_task_list.
+
+**Callbacks**  
+If you wish to get callbacks for 'idle' or 'watchdog' then define callback functions and call set_idle_callback and set_watchdog_callback to tell the scheduler.  
+The callbacks may be global, static or member function, wrapped in an etl::function.
+
+**Starting the scheduler**  
+The scheduler is started by calling `start()`.
+
+## Example
+
+An example of the scheduler can be found in the repository in `examples/Scheduler`.

docs/frameworks/finite-state-machine.md

@@ -1,15 +1,21 @@
-Finite State Machine
+---
+title: "Finite State Machine"
+---
 
-This page documents version 20.0.0 and above.
-For version 19.x.x or earlier see this page.
+{{< callout type="info">}}
+  Header: `fsm.h`  
+{{< /callout >}}
 
-A finite state machine driven by the reception of events (messages) . The incoming messages will be automatically routed to specific handlers based on the message list defined in the template parameters. Optional on_entry and on_exit handlers are available.
+This page documents version `20.0.0` and above.  
 
-This FSM is slightly more involved to set up than the traditional simple table driven method, but provides great flexibility in implementation. It may also be faster due to  the fact that all messages are routed through a direct switch/case/call method rather than scanning a lookup table and calling indirectly through function pointers.
+A finite state machine driven by the reception of events (messages) . The incoming messages will be automatically routed to specific handlers based on the message list defined in the template parameters. Optional on_entry and on_exit handlers are available.  
 
-The on_event functions are not virtual. The template class uses CRTP to directly call the derived class's functions.
+This FSM is slightly more involved to set up than the traditional simple table driven method, but provides great flexibility in implementation. It may also be faster due to the fact that all messages are routed with either O(1) or O(N) rather than scanning a lookup table and calling indirectly through function pointers.  
 
-Defines the following classes:-
+The `on_event` functions are not virtual. The template class uses [CRTP](https://en.wikipedia.org/wiki/Curiously_recurring_template_pattern) to directly call the derived class's functions.  
+
+**Defines the following classes**  
+```cpp
 etl::ifsm_state
 etl::fsm_state <<template>>
 etl::fsm
@@ -17,188 +23,291 @@ etl::fsm_exception
 etl::fsm_null_state_exception
 etl::fsm_state_id_exception
 etl::fsm_state_list_exception
+```
 
+---
+
+```cpp
 template <typename... TStates>
 class fsm_state_pack 
-A class to store FSM states.
-Static asserts if state IDs are not 0..N-1 and in order
-Static asserts if there are no states
-Static asserts if any state IDs are greater or equal to etl::No_State_Change
-20.43.0
+```
+A class to store FSM states.  
+Static asserts if state IDs are not 0..N-1 and in order.  
+Static asserts if there are no states.  
+Static asserts if any state IDs are greater or equal to `etl::No_State_Change`.  
+Since: `20.43.0`
 
-Note: This header is a generated from fsm_generator.h. To handle more than the standard 16 message types then a new one must be generated.
-See Generators
-____________________________________________________________________________________________________
-Types
+Note: This header is a generated from `fsm_generator.h`. For C++03, to handle more than the standard 16 message types then a new one must be generated.  
 
+## Types
+
+```cpp
 etl::fsm_state_id_t
-By default is defined as uint_least8_t.
-If the user defines ETL_FSM_STATE_ID_TYPE then the type will be set to this.
-____________________________________________________________________________________________________
+```
+By default is defined as `uint_least8_t`.  
+If the user defines `ETL_FSM_STATE_ID_TYPE` then the type will be set to this.
+
+```cpp
 ifsm_state
-
+```
 The base for all FSM states.
-____________________________________________________________________________________________________
-etl::fsm_state_id_t get_state_id() const
-Returns the id of the state.
-____________________________________________________________________________________________________
-virtual fsm_state_id_t process_event(const etl::imessage& message) = 0
 
-The etl::fsm_state will override this.
+---
+
+```cpp
+etl::fsm_state_id_t get_state_id() const
+```
+Returns the id of the state.
+
+---
+
+```cpp
+virtual fsm_state_id_t process_event(const etl::imessage& message) = 0
+```
+The `etl::fsm_state` will override this.  
 Processes the event message from the specified source.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 virtual fsm_state_id_t on_enter_state()
-By default returns No_State_Change.
+```
+By default returns `No_State_Change`.  
 The derived state should override this to provide alternative behaviour.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 virtual void on_exit_state()
-By default does nothing.
+```
+By default does nothing.  
 The derived state should override this to provide alternative behaviour.
-____________________________________________________________________________________________________
+
+```cpp
 void add_child_state(etl::ifsm_state& state)
-Adds the specified state as a child state.
-The first state added will be the default state.
-This is only of use when used with an etl::hsfm instance.
-____________________________________________________________________________________________________
+```
+Adds the specified state as a child state.  
+The first state added will be the default state.  
+This is only of use when used with an `etl::hsfm` instance.  
+
+---
+
+```cpp
 template <typename TSize>
 void set_child_states(etl::ifsm_state** state_list, TSize size)
-Sets the list of child states.
-Sets the default state to the first in the list.
+```
+Sets the list of child states.  
+Sets the default state to the first in the list.  
 Each state is modified to set it's parent state pointer.
-This is only of use when used with an etl::hsfm instance.
-____________________________________________________________________________________________________
-Constants
+This is only of use when used with an `etl::hsfm` instance.  
 
+## Constants
+
+```cpp
 static ETL_CONSTANT fsm_state_id_t No_State_Change
+```
 The return value to indicate that the state will not change.
-____________________________________________________________________________________________________
-fsm_state
-A templated state base. Inherits from etl::ifsm_state.
-____________________________________________________________________________________________________
-Template parameters
 
-For C++03 to C++14
-TContext The FSM context class. i.e. The class derived from etl::fsm.
-TDerived The derived state.
-T1       The first message type.
-T2...    The additional message types.
-         The maximum number of types can be set by running the generator for this file. The default is 16
-____________________________________________________________________________________________________
-For C++17 and above
-TContext          The FSM context class. i.e. The class derived from etl::fsm.
-TDerived          The derived state.
-TMessage_Types... The message types.
+## fsm_state
+A templated state base. Inherits from `etl::ifsm_state`.
 
-This definition will automatically be selected if the compiler supports C++17. It uses fold expressions to resolve on_event() calls.
-To use the older C++03 compatible definition, define ETL_FSM_FORCE_CPP03 as a project setting or in the optional etl_profile.h.
-____________________________________________________________________________________________________
-The derived class must define the following member functions.
+## Template parameters
 
+**For C++03**  
+
+`TContext` The FSM context class. i.e. The class derived from `etl::fsm`.  
+`TDerived` The derived state.  
+`T1`       The first message type.  
+`T2...`    The additional message types.  
+
+The maximum number of types can be set by running the generator for this file. The default is 16
+
+**For C++11 and above**  
+`TContext`          The FSM context class. i.e. The class derived from `etl::fsm`.  
+`TDerived`          The derived state.  
+`TMessage_Types...` The message types.  
+
+This definition will automatically be selected if the compiler supports C++11 or greater.  
+To use the older C++03 compatible definition, define `ETL_FSM_FORCE_CPP03` as a project setting or in the optional `etl_profile.h`.  
+
+---
+
+The derived class must define the following member functions.  
+
+```cpp
 etl::fsm_state_id_t on_event(const Type& msg);
-sender The originator of the message.
-msg    The event message. A const reference to the concrete message type.
-Replace Type with the concrete message type.
-And so on for all of the template parameter types.
-Returns the id of the next state.
-____________________________________________________________________________________________________
+```
+`msg`    The event message. A const reference to the concrete message type.  
+Replace Type with the concrete message type.  
+And so on for all of the template parameter types.  
+Returns the id of the next state.  
+
+---
+
+```c++
 etl::fsm_state_id_t on_event_unknown(const etl::imessage& msg);
-sender The originator of the message.
-msg    The event message.  A const reference to the base message type.
-Called when a message type is received that is not in the template list.
+```
+`msg`    The event message.  A const reference to the base message type.  
+Called when a message type is received that is not in the template list.  
 Returns the id of the next state.
-____________________________________________________________________________________________________
-Member Functions
 
+## Member Functions
+
+```cpp
 TContext& get_fsm_context() const
-Gets a reference to the FSM context.
-This is the class that was derived from etl::fsm.
-____________________________________________________________________________________________________
-Enumerations
+```
+Gets a reference to the FSM context.  
+This is the class that was derived from `etl::fsm`.
 
-STATE_ID The id of this state.
-____________________________________________________________________________________________________
-fsm
-The state machine.
-Inherits from etl::imessage_router.
-____________________________________________________________________________________________________
+## Enumerations
+
+`STATE_ID` The id of this state.
+
+## fsm
+The state machine.  
+Inherits from `etl::imessage_router`.  
+
+---
+
+```cpp
 fsm(etl::message_router_id_t id)
-Constructor.
-Sets the router id for the FSM.
+```
+Constructor.  
+Sets the router id for the FSM.  
 The FSM is not started.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 template <typename TSize>
 void set_states(etl::ifsm_state** p_states, TSize size)
-Set the states for the FSM
-Emits an etl::fsm_state_list_exception if size is zero.
-Emits an etl::fsm_state_list_exception if states are in the incorrect id order.
-Emits an etl::fsm_null_state_exception if any of the state pointers is null.
+```
+Set the states for the FSM.  
+Emits an etl::fsm_state_list_exception if size is zero.  
+Emits an etl::fsm_state_list_exception if states are in the incorrect id order.  
+Emits an etl::fsm_null_state_exception if any of the state pointers is null.  
 
-Note: The pointers to the states in the state list must be at the index specified by the state id.
-i.e. In the example below stateList[StateId::IDLE] == &idle
-____________________________________________________________________________________________________
+Note: The pointers to the states in the state list must be at the index specified by the state id.  
+i.e. In the example below `stateList[StateId::IDLE] == &idle`  
+
+---
+
+```cpp
 template <typename... TStates>
 void set_states(etl::fsm_state_pack<TStates...>& state_pack)
+```
 Set the states for the FSM
-____________________________________________________________________________________________________
-void start(bool call_on_enter_state = true);
-Starts the FSM.
-If call_on_enter_state is true then on_enter_state is called for the initial state. Default is true.
-Can only be called once.
+
+---
+
+```cpp
+void start(bool call_on_enter_state = true)
+```
+Starts the FSM.  
+If `call_on_enter_state` is `true` then on_enter_state is called for the initial state. Default is `true`.  
+Can only be called once.  
 Subsequent calls will do nothing.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 void receive(const etl::imessage& message)
+```
 Top level message handler for the FSM.
-___________________________________________________________________________________________________
+
+---
+
+```cpp
 void receive(etl::message_router_id_t destination_router_id, 
              const etl::imessage&     message)
-Top level message handler for the FSM.
+```
+Top level message handler for the FSM.  
 If the destination id is not the FSM's id, then the message is ignored.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 bool accepts(etl::message_id_t id) const
+```
+Returns `true`.
 
-Returns true.
-____________________________________________________________________________________________________
+---
+
+```cpp
 etl::fsm_state_id_t get_state_id() const
+```
 Gets the current state id.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 ifsm_state& get_state()
-Gets a reference to the current state interface.
-Emits an etl::etl::fsm_null_state_exception if the current state is null.
-____________________________________________________________________________________________________
+```
+Gets a reference to the current state interface.  
+Emits an `etl::etl::fsm_null_state_exception` if the current state is null.
+
+---
+
+```cpp
 const ifsm_state& get_state() const
-Gets a const reference to the current state interface.
-Emits an etl::etl::fsm_null_state_exception if the current state is null.
-____________________________________________________________________________________________________
+```
+Gets a const reference to the current state interface.  
+Emits an `etl::etl::fsm_null_state_exception` if the current state is null.
+
+---
+
+```cpp
 bool is_started() const
+```
 Checks if the FSM has been started.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 void reset(bool call_on_exit_state = false)
-Resets the FSM to its pre-started state.
-If call_on_exit_state is true then on_exit_state is called for the current state. Default is false.
-____________________________________________________________________________________________________
+```
+Resets the FSM to its pre-started state.  
+If `call_on_exit_state` is `true` then `on_exit_state` is called for the current state. Default is `false`.
+
+---
+
+```cpp
 etl::fsm_state_id_t transition_to(etl::fsm_state_id_t new_state_id)
-Invokes a state transition.
+```
+Invokes a state transition.  
 Returns the new state id.
-____________________________________________________________________________________________________
-Errors
 
+## Errors
+```cpp
 fsm_exception
-Inherits from etl::exception
+```
+Inherits from `etl::exception`.
 
+---
+
+```cpp
 fsm_null_state_exception
-Inherits from etl::fsm_exception
+```
+Inherits from `etl::fsm_exception`
 
+---
+
+```cpp
 fsm_state_id_exception
-Inherits from etl::fsm_exception
+```
+Inherits from `etl::fsm_exception`
 
+---
+
+```cpp
 fsm_state_list_exception
-Inherits from etl::fsm_exception
-____________________________________________________________________________________________________
-Example
+```
+Inherits from `etl::fsm_exception`
 
-An example of a queued FSM can be found in the repository in examples\QueuedFSM
-____________________________________________________________________________________________________
+## Example
+An example of a queued FSM can be found in the repository in `examples\QueuedFSM`
 
+```cpp
 const etl::message_router_id_t MOTOR_CONTROL = 0;
 
 //***************************************************************************
@@ -430,5 +539,4 @@ motorControl.receive(Start());
 
 // Receive a Stop(emergency) event. The next state is 'IDLE'.
 motorControl.receive(Stop(true));
-
-
+```

docs/frameworks/hierarchical-finite-state-machine.md

@@ -0,0 +1,100 @@
+---
+title: "Hierarchical Finite State Machine"
+---
+
+{{< callout type="info">}}
+  Header: `hfsm.h`  
+  Since: `20.10.0`
+{{< /callout >}}
+
+Hierarchical Finite State Machine  
+
+The ETL's `etl::hfsm` is derived from etl::fsm and utilises the same state template classes.  
+See `etl::fsm`  
+
+Note:  
+For an `etl::hfsm`, `on_enter_state()` cannot force a state change. It must return `etl::ifsm_state::No_State_Change`.  
+If it does not, then an `ETL_ASSERT` will be raised.  
+
+Defines `etl::hfsm` plus all defined in `fsm.h`.
+
+## hfsm
+The state machine.  
+Inherits from `etl::fsm`.
+
+```cpp
+hfsm(etl::message_router_id_t id)
+```
+Constructor.  
+Sets the router id for the HFSM.  
+The HFSM is not started.
+
+```cpp
+void receive(const etl::imessage& message)
+```
+Top level message handler for the HFSM.
+
+## Errors
+Additional errors to `etl::fsm`.
+
+```cpp
+fsm_state_composite_state_change_forbidden
+```
+Inherits from `etl::fsm_exception`
+
+**Example**  
+
+![image](hfsm.png)
+
+**The states**  
+```cpp
+Idle        idle;
+Running     running;
+WindingUp   windingUp;
+WindingDown windingDown;
+AtSpeed     atSpeed;
+
+struct StateId
+{
+  enum
+  {
+    Idle,
+    Running,
+    Winding_Up,
+    Winding_Down,
+    At_Speed,
+    Number_Of_States
+  };
+}
+
+struct EventId
+{
+  enum
+  {
+    Start,
+    Stop,
+    EStop,
+    Stopped,
+    Set_Speed,
+    Timeout
+  };
+};
+
+// These are all of the states for this HSFM.
+etl::ifsm_state* stateList[StateId::Number_Of_States] =
+{
+  &idle, &running, &windingUp, &windingDown, &atSpeed
+};
+
+// These states are child states of 'Running'.
+etl::ifsm_state* childStates[] =
+{
+  &windingUp, &atSpeed, &windingDown
+};
+
+MotorControl motorControl;
+
+running.set_child_states(childStates, etl::size(childStates));
+
+motorControl.Initialise(stateList, etl::size(stateList));
+```

docs/frameworks/task.md

@@ -0,0 +1,75 @@
+---
+title: "task"
+---
+
+{{< callout type="info">}}
+  Header: `task.h`  
+{{< /callout >}}
+
+The base for tasks controlled by `etl::scheduler`.
+
+## Types
+
+`etl::task_priority_t`
+The type for task priorities.
+
+## task
+
+```cpp
+task(task_priority_t priority)
+```
+Constructor.  
+Sets the task priority.
+
+---
+
+```cpp
+virtual ~task();
+```
+Virtual destructor
+
+---
+
+```cpp
+virtual uint32_t task_request_work() const = 0;
+```
+The derived task must override this.  
+Should return a value that represents the amount of work to do. This may be the number of items in the task's message queue, for example.  
+Return zero if the task requires no processing time.  
+
+---
+
+```cpp
+virtual void task_process_work() = 0;
+```
+The derived task must override this.  
+The task should process one unit of work.
+
+---
+
+```cpp
+virtual void on_task_added()
+```
+The derived task may override this.  
+By default, does nothing.  
+Since: `19.4.0`
+
+---
+
+```cpp
+void set_task_running(bool task_running)
+```
+Enables/disables the task from processing work.  
+Enabled by default.
+
+---
+
+```cpp
+bool task_is_running() const;
+```
+Returns `true` if the task is in the 'running' state.
+
+```cpp
+etl::task_priority_t get_task_priority() const
+```
+Returns the priority of the task.

docs/patterns/singleton-base.md

@@ -0,0 +1,53 @@
+---
+title: "singleton_base"
+---
+
+{{< callout type="info">}}
+  Header: `singleton_base.h`  
+{{< /callout >}}
+
+Allows creation of a singleton base class.  
+
+```cpp
+etl::singleton_base<typename T>
+```
+`T` The type to use as a singleton.  
+
+The class derived derived from this must call the constructor with the instance of itself.  
+Multiple calls to the constructor will result in an `etl::singleton_base_already_created` assertion.  
+
+Before the constructor Is called, the singleton is in the invalid state.  
+
+See also `etl::singleton`
+
+## Static functions
+
+```cpp
+static T& instance()
+```
+Returns a reference to the one instance of `T`.  
+Asserts an `etl::singleton_base_not_created` if the instance has not been attached.
+
+---
+
+```cpp
+static bool is_valid()
+```
+Returns `true` if the instance is has been attached, otherwise `false`.
+
+## Example
+
+```cpp
+class MyType : public etl::singleton_base<MyType>
+{
+ MyType()
+   : etl::singleton_base<MyType>(*this)
+  {
+  }
+};
+
+bool is_valid;
+is_valid = MyType::is_valid();   // true
+
+MyType& mt = MyType::instance(); // Get the instance
+```

docs/patterns/singleton.md

@@ -1,62 +1,107 @@
-Singleton
+---
+title: "singleton"
+---
 
-Allows creation of a singleton, with deterministic construction and destruction.
+{{< callout type="info">}}
+  Header: `singleton.h`  
+{{< /callout >}}
 
+Allows creation of a singleton, with deterministic construction and destruction.  
+
+```cpp
 etl::singleton<typename T>
-T The type to use as a singleton.
+```
+`T` The type to use as a singleton.
 
-Before create Is called, the singleton is in the invalid state.
+Before create Is called, the singleton is in the invalid state.  
 
-See also etl::singleton_base
-____________________________________________________________________________________________________
-Static functions
+See also `etl::singleton_base`.
 
-C++03 and below.
+## Static functions
+
+**C++03 and below.**  
+```cpp
 static void create()
-Creates the singleton. Default constructs the instance.
-Sets the singleton to the valid state.
-Only the first call to create is effective.
-Must be called before any calls to instance().
+```
+Creates the singleton. Default constructs the instance.  
+Sets the singleton to the valid state.  
+Only the first call to create is effective.  
+Must be called before any calls to `instance()`.
 
+---
+
+```cpp
 template <typename T1>
 static void create(const T1& p1)
+```
 Construct from 1 parameter.
 
+---
+
+```cpp
 template <typename T1, typename T2>
 static void create(const T1& p1, const T2& p2)
+```
 Construct from 2 parameters.
 
+---
+
+```cpp
 template <typename T1, typename T2, typename T3>
 static void create(const T1& p1, const T2& p2, const T3& p3)
+```
 Construct from 3 parameters.
 
+---
+
+```cpp
 template <typename T1, typename T2, typename T3, typename T4>
 static void create(const T1& p1, const T2& p2, const T3& p3, const T4& p4)
+```
 Construct from 4 parameters.
-____________________________________________________________________________________________________
-C++11 and above.
+
+---
+
+**C++11 and above.**  
+```cpp
 template <typename... TArgs>
 static void create(TArgs&&... args)
-Creates the singleton and constructs the type using the supplied parameters.
-Sets the singleton to the valid state.
-Only the first successful call to create is effective. Does nothing if the singleton is already valid.
-Must be called before any calls to instance().
-____________________________________________________________________________________________________
-static T& instance()
-Returns a reference to the one instance of T.
-Asserts an etl::singleton_not_created if create has not been called.
-____________________________________________________________________________________________________
-static void destroy()
-Calls the destructor of the instance.
-Sets the singleton to the invalid state.
-Only the first successful call to destroy is effective. Does nothing if the singleton is already invalid.
-____________________________________________________________________________________________________
-static bool is_valid()
-Returns true if the instance is valid.
-Returns false before create and after destroy are called.
-____________________________________________________________________________________________________
-Example
+```
+Creates the singleton and constructs the type using the supplied parameters.  
+Sets the singleton to the valid state.  
+Only the first successful call to create is effective. Does nothing if the singleton is already valid.  
+Must be called before any calls to `instance()`.
 
+---
+
+```cpp
+static T& instance()
+```
+Returns a reference to the one instance of `T`.  
+Asserts an `etl::singleton_not_created` if create has not been called.
+
+---
+
+```cpp
+static void destroy()
+```
+Calls the destructor of the instance.  
+Sets the singleton to the invalid state.  
+Only the first successful call to destroy is effective. Does nothing if the singleton is already invalid.
+
+---
+
+```cpp
+static bool is_valid()
+```
+Returns `true` if the instance is valid.  
+Returns `false` before `create` and after `destroy` are called.
+
+---
+
+## Example
+
+```cpp
 class MyType;
 using MySingleton = etl::singleton<MyType>;
 bool is_valid;
@@ -73,7 +118,4 @@ is_valid = MySingleton::is_valid();    // true
 
 MySingleton::destroy();                // Destruct the instance
 is_valid = MySingleton::is_valid();    // false
-
-
-
-
+```

docs/patterns/visitor.md

@@ -1,66 +1,82 @@
-Visitor
-A set of template classes to enable the easy creation of objects using the Visitor pattern.
-The purpose of these classes is to create a base classes with pure virtual functions for each supplied type. 
-Any derived class that tries to instantiate an object from it will then be forced to supply an overridden version for each and every function. See the tutorial.
+---
+title: "visitor"
+---
 
-There are two templated classes:-
+{{< callout type="info">}}
+  Header: `visitor.h`  
+{{< /callout >}}
 
-____________________________________________________________________________________________________
-visitable
-The visitable base class. 
+A set of template classes to enable the easy creation of objects using the Visitor pattern.  
+The purpose of these classes is to create a base classes with pure virtual functions for each supplied type.   
+Any derived class that tries to instantiate an object from it will then be forced to supply an overridden version for each and every function.  
 
-Classes derived from this are visitable by the types declared in the template parameter list. A pure virtual accept function will be created for each visitor type.
+There are two templated classes; `visitor` and `visitable`.
 
-C++03
+## visitable
+The visitable base class.  
+
+Classes derived from this are visitable by the types declared in the template parameter list. A pure virtual `accept` function will be created for each visitor type.  
+
+**C++03**  
 Up to four visitor types may be specified. 
 
+```cpp
 template <typename T1, typename T2 = void, typename T3 = void, typename T4 = void>
-class visitable
+class visitable;
+```
 
-____________________________________________________________________________________________________
-
-C++11 and above
+**C++11 and above**  
 Any number of visitor types may be specified.
 
+```cpp
 template <typename... Types>
 class visitable;
+```
 
-____________________________________________________________________________________________________
-visitor
-The visitor base class. 
-Classes derived from this can be passed to objects derived from visitable.
-A pure virtual visit function will be created for each specified type.
+## visitor
+The visitor base class.  
+Classes derived from this can be passed to objects derived from `visitable`.  
+A pure virtual `visit` function will be created for each specified type.  
 
-C++03
+**C++03**  
  Up to sixteen types may be specified in the template parameter list
 
+```cpp
 template <typename T1,         typename T2  = void, typename T3  = void, typename T4  = void,
-          typename T5  = void, typename T6  = void, typename T7  = void, typename T8  = void,
+      0    typename T5  = void, typename T6  = void, typename T7  = void, typename T8  = void,
           typename T9  = void, typename T10 = void, typename T11 = void, typename T12 = void, 
           typename T13 = void, typename T14 = void, typename T15 = void, typename T16 = void>
-class visitor
-____________________________________________________________________________________________________
-C++11 and above
-Any number of types may be specified.
+class visitor;
+```
 
+**C++11 and above**
+Any number of types may be specified.  
+
+```cpp
 template <typename... Types>
-class visitor
-____________________________________________________________________________________________________
-is_visitor
-Detects whether a type is a visitor.
-20.37.0
+class visitor;
+```
 
+## is_visitor
+Detects whether a type is a visitor.  
+Since: `20.37.0`.
+
+```cpp
 template <typename T>
 struct is_visitor;
-Derived from etl::bool_constant
-____________________________________________________________________________________________________
-C++17 and above.
+```
+Derived from `etl::bool_constant`
+
+**C++17 and above**  
+```cpp
 template <typename T>
 struct is_visitor_v;
-____________________________________________________________________________________________________
-Example
+```
 
-Before 20.37.0
+## Example
+
+Before: `20.37.0`
+```cpp
 All arguments are passed by reference.
 
 class Square;
@@ -115,10 +131,14 @@ Triangle triangle;
 square.accept(visitor);   // visitor's visit(Square) is called.
 circle.accept(visitor);   // visitor's visit(Circle&) is called.
 triangle.accept(visitor); // visitor's visit(const Triangle&) is called.
-____________________________________________________________________________________________________
-From 20.37.0
+```
+
+---
+
+Since: `20.37.0`  
 Arguments are passed according to the template parameters.
 
+```cpp
 class Square;
 class Circle;
 class Triangle;
@@ -171,5 +191,4 @@ Triangle triangle;
 square.accept(visitor);   // visitor's visit(Square) is called.
 circle.accept(visitor);   // visitor's visit(Circle&) is called.
 triangle.accept(visitor); // visitor's visit(const Triangle&) is called.
-
-
+```

docs/raw/frameworks/Cooperative Scheduler.txt

@@ -1,183 +0,0 @@
-Cooperative Scheduler
-
-A lightweight cooperative multi-tasking scheduler.
-Can be used stand-alone or in conjunction with a messaging system such as the ETL's message router or FSM as the back-end handler. For use when a complex OS or RTOS is overkill.
-
-Calls an 'idle' callback whenever the scheduler returns true.
-Calls a 'watchdog' callback whenever the scheduler returns.
-
-The scheduler makes use of etl::task.
-
-____________________________________________________________________________________________________
-Scheduling Policies
-A number of built-in scheduling policies are available.
-Note: The tasks are stored in decreasing priority id order. i.e. Higher id = higher priority.
-
-____________________________________________________________________________________________________
-Sequential Single
-etl::scheduler_policy_sequential_single
-
-A sequential algorithm that calls a task if it has work to do , starting from the highest priority task.
-On return, it moves to the next task in the list. At the end of the list it returns the idle status.
-If no tasks with work were found then the idle status is set to true.
-
-____________________________________________________________________________________________________
-Sequential Multiple
-etl::scheduler_policy_sequential_multiple
-
-A sequential algorithm that calls a task if it has work to do , starting from the highest priority task.
-On return, it calls the task again if it still has work, otherwise it moves to the next task in the list.
-At the end of the list it returns the idle status.
-If no tasks with work were found then the idle status is set to true.
-
-____________________________________________________________________________________________________
-Highest Priority
-etl::scheduler_policy_highest_priority
-
-An algorithm that calls the highest priority task that has work to do.
-Returns the idle status.
-If no tasks with work were found then the idle status is set to true.
-
-____________________________________________________________________________________________________
-Most Work
-etl::scheduler_policy_most_work
-
-An algorithm that calls the task that has the most work to do, starting from the highest priority task.
-Returns the idle status.
-If no tasks with work were found then the idle status is set to true.
-
-____________________________________________________________________________________________________
-Custom Scheduler
-Creating a custom scheduler policy is simple.
-Just create a structure with the following signature and add your own scheduling algorithm.
-To get 'idle' callbacks then the policy must regularly return true.
-To get 'watchdog' callbacks then the policy must regularly return.
-
-struct scheduler_policy_custom
-{
-  bool schedule_tasks(etl::ivector<etl::task*>& task_list)
-  {
-    bool idle = true;
-
-    //**************************************
-    // Add your scheduling policy here.
-    // Set 'idle' to false if any tasks were run.
-    //**************************************
-
-    return idle;
-  }
-};
-
-____________________________________________________________________________________________________
-ischeduler
-Can be used as a reference to all scheduler instances.
-
-ischeduler()
-
-Constructor
-
-____________________________________________________________________________________________________
-void set_idle_callback(etl::ifunction<void>& callback);
-
-Sets the function to be called when idle.
-
-____________________________________________________________________________________________________
-void set_watchdog_callback(etl::ifunction<void>& callback);
-
-Sets the function to be called to reset the watchdog.
-
-____________________________________________________________________________________________________
-void set_scheduler_running(bool scheduler_running);
-
-Sets the running state of the scheduler.
-
-____________________________________________________________________________________________________
-bool scheduler_is_running() const;
-
-Gets the running state of the scheduler.
-
-____________________________________________________________________________________________________
-void exit_scheduler()
-
-Instructs the scheduler to exit after the next idle call.
-
-____________________________________________________________________________________________________
-void add_task(etl::task& task);
-
-Adds a task to the task list.
-The task list is in priority order where higher id = higher priority. Tasks with duplicate ids are in insert order.
-Emits an etl::scheduler_too_many_tasks_exception if the task list is full.
-
-____________________________________________________________________________________________________
-template <typename TSize>
-void add_task_list(etl::task** p_tasks, TSize size);
-
-Emits an etl::scheduler_too_many_tasks_exception if the task list is full.
-Emits an etl::scheduler_null_task_exception if any of the task pointers is null.
-
-____________________________________________________________________________________________________
-virtual void start()
-
-Starts the scheduler.
-
-____________________________________________________________________________________________________
-scheduler
-Inherits from etl::ischeduler.
-
-____________________________________________________________________________________________________
-Template Parameters
-
-TSchedulerPolicy The policy to use schedule tasks.
-MAX_TASKS        The maximum number of tasks to schedule.
-
-____________________________________________________________________________________________________
-Member Functions
-
-scheduler()
-
-Constructor.
-
-void start()
-
-Starts the scheduler.
-Emits an etl::scheduler_no_tasks_exception if there are no tasks in the list.
-
-____________________________________________________________________________________________________
-Errors
-
-scheduler_exception
-Inherits from etl::exception
-
-scheduler_no_tasks_exception
-Inherits from etl::scheduler_exception
-
-scheduler_null_task_exception
-Inherits from etl::scheduler_exception
-
-____________________________________________________________________________________________________
-Overview of use
-As a basic example, you will have to define the following...
-
-Tasks
-For each of your tasks, derive a class from etl::task and overide the two virtual functions uint32_t task_request_work() const and void task_process_work(). task_request_work returns a value that informs the scheduler that this task has work to process. The return value should be non-zero if the task has work. This meaning of this is user defined, it could be the number of messages in the task's queue, or just a 0 = no work, 1 = have work. task_process_work allows the task to process any work that it has. How much work it processes on each call is user defined; often it will be one 'unit' of work and letting the policy determine which task gets the next opportunity to process more.
-
-Task list
-An array of pointers to the tasks. Passed to the scheduler with add_task_list.
-Use add_task to add additional tasks.
-
-The scheduler
-An instance of etl::scheduler with the required scheduling policy.
-Initialise the task list by calling add_task_list.
-
-Callbacks
-If you wish to get callbacks for 'idle' or 'watchdog' then define callback functions and call set_idle_callback and set_watchdog_callback to tell the scheduler.
-The callbacks may be global, static or member function, wrapped in an etl::function.
-
-Starting the scheduler
-The scheduler is started by calling start().
-
-____________________________________________________________________________________________________
-Example
-
-An example of the scheduler can be found in the repository in examples/Scheduler
-

docs/raw/frameworks/Hierarchical Finite State Machine.txt

@@ -1,98 +0,0 @@
-Hierarchical Finite State Machine
-20.10.0
-
-The ETL's etl::hfsm is derived from etl::fsm and utilises the same state template classes.
-See etl::fsm
-
-Note:
-For an etl::hfsm, on_enter_state() cannot force a state change. It must return etl::ifsm_state::No_State_Change.
-If it does not, then an ETL_ASSERT will be raised.
-
-Defines etl::hfsm plus all defined in fsm.h.
-____________________________________________________________________________________________________
-hfsm
-
-The state machine.
-Inherits from etl::fsm.
-____________________________________________________________________________________________________
-hfsm(etl::message_router_id_t id)
-Constructor.
-Sets the router id for the HFSM.
-The HFSM is not started.
-____________________________________________________________________________________________________
-void receive(const etl::imessage& message)
-Top level message handler for the HFSM.
-____________________________________________________________________________________________________
-Errors
-
-Additional errors to etl::fsm.
-
-fsm_state_composite_state_change_forbidden
-Inherits from etl::fsm_exception
-____________________________________________________________________________________________________
-Example
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-// The states.
-Idle        idle;
-Running     running;
-WindingUp   windingUp;
-WindingDown windingDown;
-AtSpeed     atSpeed;
-
-struct StateId
-{
-  enum
-  {
-    Idle,
-    Running,
-    Winding_Up,
-    Winding_Down,
-    At_Speed,
-    Number_Of_States
-  };
-}
-
-struct EventId
-{
-  enum
-  {
-    Start,
-    Stop,
-    EStop,
-    Stopped,
-    Set_Speed,
-    Timeout
-  };
-};
-
-// These are all of the states for this HSFM.
-etl::ifsm_state* stateList[StateId::Number_Of_States] =
-{
-  &idle, &running, &windingUp, &windingDown, &atSpeed
-};
-
-// These states are child states of 'Running'.
-etl::ifsm_state* childStates[] =
-{
-  &windingUp, &atSpeed, &windingDown
-};
-
-MotorControl motorControl;
-
-running.set_child_states(childStates, etl::size(childStates));
-
-motorControl.Initialise(stateList, etl::size(stateList));
-

docs/raw/frameworks/Message Bus.txt

@@ -1,157 +0,0 @@
-Message Bus
-20.33.0
-This page documents version 20.0.0 and above.
-For version 19.x.x or earlier see this page.
-
-A variant of the observer pattern in that message routers and derived types are be able to subscribe to messages on a bus. The messages can be either broadcast, to be automatically picked up by any router that has a handler, or addressed to a particular router or router id. Message buses may be nested  by setting a successor.
-____________________________________________________________________________________________________
-imessage_bus
-Derived from imessage_router
-
-The base for all message buses.
-Inherits publicly from etl::imessage_router.
-Message buses are therefore also a type of  router.
-Objects of type etl::imessage_bus cannot be directly constructed.
-
-Member functions
-
-bool subscribe(etl::imessage_router& router);
-Subscribes an etl::imessage_router derived class to the bus.
-Returns true on success.
-____________________________________________________________________________________________________
-void unsubscribe(etl::imessage_router& router);
-Unsubscribes the specified etl::imessage_router derived class from the bus.
-Does not unsubscribe from nested buses.
-____________________________________________________________________________________________________
-void unsubscribe(etl::message_router_id_t id)
-Unsubscribes routers with the specified id from the bus.
-Does not unsubscribe from nested buses.
-
-etl::imessage::MESSAGE_BUS will unsubscribe all message buses.
-etl::imessage::ALL_MESSAGE_ROUTERS will unsubscribe all routers and buses. Equivalent to calling clear().
-____________________________________________________________________________________________________
-void receive(const etl::imessage& message);
-void receive(etl::shared_message message);
-Receives a message and distributes it to all subscribers.
-Forwards the message to any successor.
-
-The routers are called first, in order of ascending router id.
-Routers with the duplicate ids will be called in subscribe order.
-Any nested message buses are called in subscribe order.
-____________________________________________________________________________________________________
-void receive(etl::message_router_id_t destination_router_id, 
-             const etl::imessage&     message);
-void receive(etl::message_router_id_t destination_router_id, 
-             etl::shared_message message);
-Receives a message and distributes it to all subscribers that have the specified router id.
-Forwards the message to any successor.
-
-Routers with the duplicate ids will be called in subscribe order.
-Any nested message buses are called in subscribe order.
-
-Override this in a derived class if you wish to capture messages sent to the bus.
-Call the base receive function from here to allow normal operation to continue.
-____________________________________________________________________________________________________
-bool accepts(etl::message_id_t id) const;
-Always returns true.
-____________________________________________________________________________________________________
-size_t size() const;
-Returns the number of subscribers.
-____________________________________________________________________________________________________
-void clear();
-Clears the bus of all subscribers.
-
-Message buses inherit all of the public functions of etl::imessage_router.
-
-Errors
-message_bus_exception
-Base error class for etl::message_bus. Inherits from etl::exception
-____________________________________________________________________________________________________
-message_bus_too_many_subscribers
- Emitted when the number of subscribers exceeds the capacity. Inherits from etl::message_bus_exception.
-____________________________________________________________________________________________________
-message_bus
-Derived from imessage_bus.
-
-template <const uint_least8_t MAX_ROUTERS>
-class message_bus
-
-MAX_ROUTERS The maximum number of routers that can be subscribed.
-
-____________________________________________________________________________________________________
-Member functions
-
-message_bus()
-Constructs a message bus.
-Message buses always have a router id of etl::imessage::MESSAGE_BUS.
-
-message_bus(etl::imessage_router& successor)
-Constructs a message bus and sets the successor.
-Message buses always have a router id of etl::imessage::MESSAGE_BUS.
-____________________________________________________________________________________________________
-Example
-
-// Some router ids.
-enum
-{
-  ROUTER_ID_1,
-  ROUTER_ID_2,
-  ROUTER_ID_3
-};
-
-// Instances of messages.
-MessageA messageA;
-
-// Instances of message routers.
-RouterA routerA(ROUTER_ID_1);
-RouterB routerB(ROUTER_ID_1);
-RouterC routerC(ROUTER_ID_2);
-RouterD routerD(ROUTER_ID_3);
-RouterE routerE(ROUTER_ID_1);
-
-// Instances of message buses.
-etl::message_bus<4> bus1;
-etl::message_bus<2> bus2;
-etl::message_bus<1> bus3;
-
-// Subscribe bus2 & bus3 to bus1.
-bus1.subscribe(bus3);
-bus1.subscribe(bus2);
-
-// Subscribe routerB & routerA to bus1.
-bus1.subscribe(routerB);
-bus1.subscribe(routerA);
-
-// Subscribe routerD & routerC to bus2.
-bus2.subscribe(routerD);
-bus2.subscribe(routerC);
-
-// Subscribe routerE to bus3.
-bus3.subscibe(routerE);
-
-// Assume all routers accept the same messages.
-
-// Broadcast messageA to everyone.
-bus1.receive(messageA);
-
-The call order will be...
-routerB
-routerA
-routerE
-routerC
-routerD
-
-// Address messageA to routers with id ROUTER_ID_1.
-bus1.receive(ROUTER_ID_1, messageA);
-
-The call order will be...
-routerB
-routerA
-routerE
-
-// Address messageA to routers with id ROUTER_ID_3.
-bus1.receive(ROUTER_ID_3, messageA);
-
-The call order will be...
-routerD
-

docs/raw/frameworks/Messages.txt

@@ -1,82 +0,0 @@
-Messages
-
-Message types used for many of the framework classes.
-____________________________________________________________________________________________________
-message_types.h
-
-etl::message_id_t
-The type used for message ids.
-By default can hold a value between 0 and 255.
-If ETL_MESSAGE_ID_TYPE is defined then this type will be used instead.
-____________________________________________________________________________________________________
-etl::message_router_id_t
-
-The type used for message router ids.
-Can hold a value between 0 and 255.
-____________________________________________________________________________________________________
-message.h
-
-The message classes are the common communication method across all of the message capable frameworks.
-They are identified by a unique id number that specialises the base class.
-____________________________________________________________________________________________________
-imessage
-
-The base class for messages. 
-It is this class that is passed around, usually by const reference.
-The class is abstract.
-____________________________________________________________________________________________________
-etl::message_id_t get_message_id() const ETL_NOEXCEPT = 0;
-Returns the id of the message.
-____________________________________________________________________________________________________
-message
-
-message<size_t ID, typename TParent = etl::imessage>
-
-Requires an integral id as the template parameter.
-Inherits from TParent, which defaults to etl::imessage.
-TParent allows additional base interfaces or  functionality to be included.
-static asserts if TParent is not a base of etl::imessage.
-____________________________________________________________________________________________________
-ID
-The id of the message as an enum.
-Can be accessed by etl::message instances.
-____________________________________________________________________________________________________
-TParent
-The class that it inherits from. It must ultimately derive from etl::imessage.
-The default is etl::imessage.
-____________________________________________________________________________________________________
-Example
-
-enum
-{
-  START,
-  STOP,
-  SET_SPEED
-};
-
-struct MyInterface : public etl::imessage
-{
-  virtual void DoStuff() = 0;
-};
-
-// Start implements MyIterface
-struct Start : public etl::message<START, MyInterface>
-{
-  void DoStuff() override
-  {
-    // Do stuff here.  
-  }
-};
-
-struct Stop : public etl::message<STOP>
-{
-  bool isEmergencyStop;
-};
-
-struct SetSpeed : public etl::message<SET_SPEED>
-{
-  uint32_t speed;
-};
-
-void Receive(const etl::imessage& msg);
-

docs/raw/frameworks/Shared Messages.txt

@@ -1,38 +0,0 @@
-Shared Messages
-
-The type used to encapsulate reference counted messages.
-Shared messages are usually passed by value.
-
-See the Shared Message Tutorial
-____________________________________________________________________________________________________
-template <typename TPool, typename TMessage>
-shared_message(TPool& owner, const TMessage& message)
-
-Static asserts if TPool is not derived from etl::ireference_counted_message_pool
-Static asserts if TMessage not derived from etl::imessage
-
-Requires that TPool implements the following member function to allocate from the pool.
-template <typename TMessage>
-etl::ireference_counted_message* allocate(const TMessage& message)
-____________________________________________________________________________________________________
-explicit shared_message(etl::ireference_coutnted_message& message)
-Construct from a reference counted message.
-____________________________________________________________________________________________________
-shared_message(const etl::shared_message& other)
-Copy constructor.
-____________________________________________________________________________________________________
-shared_message& operator =(const etl::shared_message& other)
-Assignment operator.
-____________________________________________________________________________________________________
-~shared_message()
-Destructor.
-____________________________________________________________________________________________________
-ETL_NODISCARD etl::imessage& get_message()
-Gets a reference to the contained message.
-____________________________________________________________________________________________________
-ETL_NODISCARD const etl::imessage& get_message() const
-Gets a const reference to the contained message.
-____________________________________________________________________________________________________
-ETL_NODISCARD uint32_t get_reference_count() const
-Gets the current reference count for this shared message.
-

docs/raw/frameworks/Task.txt

@@ -1,41 +0,0 @@
-Task
-The base for tasks controlled by etl::scheduler.
-____________________________________________________________________________________________________
-Types
-
-etl::task_priority_t
-The type for task priorities.
-____________________________________________________________________________________________________
-task
-
-task(task_priority_t priority)
-Constructor.
-Sets the task priority.
-____________________________________________________________________________________________________
-virtual ~task();
-Virtual destructor
-____________________________________________________________________________________________________
-virtual uint32_t task_request_work() const = 0;
-The derived task must override this.
-Should return a value that represents the amount of work to do. This may be the number of items in the task's message queue, for example.
-Return zero if the task requires no processing time.
-____________________________________________________________________________________________________
-virtual void task_process_work() = 0;
-The derived task must override this.
-The task should process one unit of work.
-____________________________________________________________________________________________________
-virtual void on_task_added(); 19.4.0
-The derived task may override this.
-By default, does nothing.
-____________________________________________________________________________________________________
-void set_task_running(bool task_running);
-Enables/disables the task from processing work.
-Enabled by default.
-____________________________________________________________________________________________________
-bool task_is_running() const;
-Returns true if the task is in the 'running' state.
-____________________________________________________________________________________________________
-etl::task_priority_t get_task_priority() const;
-Returns the priority of the task.
-
-

docs/raw/frameworks/message_packet.txt

@@ -1,103 +0,0 @@
-message_packet
-
-A container for more than one type of message.
-The messages must have been derived from etl::imessage.
-
-The messages types that the packet may contain are listed as template parameters.
-e.g. etl::message_packet<Message1, Message2, Message3>
-
-From 20.40.0 message types are not rquired to have a virtual destructor.
-
-____________________________________________________________________________________________________
-message_packet()
-Default constructs a message packet.
-is_valid() returns false.
-___________________________________________________________________________________________________
-explicit message_packet(const etl::imessage&)
-Constructs a message packet from an etl::imessage reference.
-Asserts an etl::unhandled_message_exception error if the parameter is not one listed in the template parameter list.
-___________________________________________________________________________________________________
-explicit message_packet(etl::imessage&&) C++11
-Move constructs a message packet from an etl::imessage rvalue reference.
-Emits an etl::unhandled_message_exception error if the parameter is not one listed in the template parameter list.
-___________________________________________________________________________________________________
-20.22.0
-template <typename TMessage>
-explicit message_packet(const TMessage&)
-Constructs a message packet from a TMessage reference.
-Emits a compile time static assert if the parameter is not one listed in the template parameter list.
-___________________________________________________________________________________________________
-20.22.0
-template <typename TMessage>
-explicit message_packet(TMessage&&) C++11
-Move constructs a message packet from a TMessage rvalue reference.
-Emits a compile time static assert if the parameter is not one listed in the template parameter list.
-___________________________________________________________________________________________________
-message_packet(const message_packet&)
-Constructs a message packet from an message_packet reference.
-Emits an etl::unhandled_message_exception error if the parameter is not one listed in the template parameter list.
-___________________________________________________________________________________________________
-message_packet(message_packet&&)
-Move constructs a message packet from an message_packet rvalue reference.
-Emits an etl::unhandled_message_exception if the parameter is not one listed in the template parameter list.
-___________________________________________________________________________________________________
-message_packet& operator =(const message_packet&)
-Assigns a message packet from an message_packet reference.
-Emits an etl::unhandled_message_exception error if the parameter is not one listed in the template parameter list.
-___________________________________________________________________________________________________
-message_packet& operator =(message_packet&&)
-Move assigns a message packet from an message_packet rvalue reference.
-Emits an etl::unhandled_message_exception error if the parameter is not one listed in the template parameter list.
-___________________________________________________________________________________________________
-etl::imessage& get()
-const etl::imessage& get() const
-Returns a reference to an etl::imessage
-___________________________________________________________________________________________________
-bool is_valid() const
-Returns true if the packet contains a valid message, otherwise false.
-____________________________________________________________________________________________________
-Constants
-
-SIZE      The size of the largest message.
-ALIGNMENT The largest message alignment.
-____________________________________________________________________________________________________
-Example
-
-enum
-{
-  MESSAGE1,
-  MESSAGE2,
-  MESSAGE3
-};
-
-struct Message1 : public etl::message<MESSAGE1>
-{
-};
-
-struct Message2 : public etl::message<MESSAGE2>
-{
-};
-
-struct Message3 : public etl::message<MESSAGE3>
-{
-};
-
-using Packet = etl::message_packet<Message1, Message2>
-
-Message1 message1;
-Message2 message2;
-Message3 message3;
-
-Packet packet1(message1);
-Packet packet2(message2);
-Packet packet3(message3); // Runtime time error! Packet does not support Message3 type.
-
-etl::imessage& m1 = message1;
-Packet packet4(m1); // Construct from an etl::imessage reference.
-
-etl::imessage& m3 = message3;
-Packet packet4(m3); // Asserts etl::unhandled_message_exception! Packet does not support Message3 type.
-
-etl::imessage& m = packet2.get(); // Get a reference to an etl::imessage from the packet.
-
-

docs/raw/patterns/Singleton Base.txt

@@ -1,41 +0,0 @@
-Singleton Base
-
-Allows creation of a singleton base class.
-
-etl::singleton_base<typename T>
-T The type to use as a singleton.
-
-The class derived derived from this must call the constructor with the instance of itself.
-Mutiple call to the constructor will result in an etl::singleton_base_already_created assertion.
-
-Before the constructor Is called, the singleton is in the invalid state.
-
-See also etl::singleton
-____________________________________________________________________________________________________
-Static functions
-
-static T& instance()
-Returns a reference to the one instance of T.
-Asserts an etl::singleton_base_not_created if the instance has not been attached.
-____________________________________________________________________________________________________
-static bool is_valid()
-Returns true if the instance is has been attached, otherwise false.
-____________________________________________________________________________________________________
-Example
-
-class MyType : public etl::singleton_base<MyType>
-{
- MyType()
-   : etl::singleton_base<MyType>(*this)
-  {
-  }
-};
-
-bool is_valid;
-is_valid = MyType::is_valid();   // true
-
-MyType& mt = MyType::instance(); // Get the instance
-
-
-
-

docs/strings/string_stream.md

@@ -2,6 +2,10 @@
 title: "string_stream"
 ---
 
+{{< callout type="info">}}
+  Header: `string_stream.h`  
+{{< /callout >}}
+
 ## Streaming types
 `string_stream`  
 `wstring_stream`  

docs/strings/string_view.md

@@ -1,27 +1,39 @@
-string_view
+---
+title: "basic_string_view"
+---
 
-This class implements a view in to a range of a C string, etl::string (+ variants), std::string (+ variants).
+{{< callout type="info">}}
+  Header: `string_view.h`  
+  Similar to:  
+  `std::basic_string_view`  
+  `std::string_view`  
+  `std::wstring_view`  
+  `std::u8string_view`  
+  `std::u16string_view`  
+  `std::u32string_view`
+{{< /callout >}}
 
-STL equivalents:
-std::basic_string_view
-std::string_view
-std::wstring_view
-std::u16string_view
-std::u32string_view
-____________________________________________________________________________________________________
-Classes
+This class implements a view in to a range of a `C` string, `etl::string` (+ variants), `std::string` (+ variants).
 
+## Classes
+
+```cpp
 etl::basic_string_view<typename T, typename TTraits = etl::char_traits<T>>
-____________________________________________________________________________________________________
-Typedefs
+```
 
-etl::string_view<typename T>
-etl::wstring_view<typename T>
-etl::u16string_view<typename T>
-etl::u32string_view<typename T>
-____________________________________________________________________________________________________
-Member types
+## Types
 
+```cpp
+etl::string_view
+etl::wstring_view
+etl::u8string_view;
+etl::u16string_view
+etl::u32string_view
+```
+
+## Member types
+
+```cpp
 value_type              T
 size_type               std::size_t
 difference_type         std::ptrdiff_t
@@ -33,128 +45,209 @@ iterator                Random access iterator
 const_iterator          Constant random access iterator
 reverse_iterator        std::reverse_iterator<iterator>
 const_reverse_iterator  std::reverse_iterator<const_iterator>
-____________________________________________________________________________________________________
-Constants
+```
 
+## Constants
+
+```cpp
 size_t npos
-An end of view indicator by the functions that expect a view index.
+```
+**Description**  
+An end of view indicator by the functions that expect a view index.  
 An error indicator for functions that return a view index.
-____________________________________________________________________________________________________
-Constructors
 
+## Constructors
+
+```cpp
 ETL_CONSTEXPR basic_string_view()
+```
+**Description**  
 Default constructor.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 ETL_CONSTEXPR basic_string_view(const T* begin, size_t size)
+```
+**Description**  
 Construct from a start and size.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 ETL_CONSTEXPR basic_string_view(const T* begin)
+```
+**Description**  
 Construct from a zero terminated string.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 ETL_CONSTEXPR basic_string_view(const etl::basic_string_view& other)
+```
+**Description**  
 Copy constructor.
-____________________________________________________________________________________________________
 
-ETL_CONSTEXPR basic_string_view(const std::basic_string_view& other)
-Construct from std::basic_string_view.
-For C++17 and STL only.
-20.39.5 and above.
-____________________________________________________________________________________________________
-Modifiers
+## Modifiers
 
+```cpp
 void remove_prefix(size_t n)
-Shrinks the view from the front.
+```
+**Description**  
+Shrinks the view from the front.  
 Undefined behaviour if n is larger than the string.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 void remove_suffix(size_t n)
-Shrinks the view from the back.
+```
+**Description**  
+Shrinks the view from the back.  
 Undefined behaviour if n is larger than the string.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 void swap(etl::basic_string_view<T, TTraits>& view)
+```
+**Description**  
 Swaps with another view.
-____________________________________________________________________________________________________
-Element access
 
+## Element access
+
+```cpp
 const T& at(size_t i) const
-Returns a const reference to the indexed element. 
-Emits an etl::string_view_uninitialised if the view is not initialised.
-Emits an etl::string_view_bounds if the index is not in range.
+```
+**Description**  
+Returns a const reference to the indexed element.  
+Emits an `etl::string_view_uninitialised` if the view is not initialised.  
+Emits an `etl::string_view_bounds` if the index is not in range.  
 If asserts or exceptions are not enabled then undefined behaviour occurs.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 const_reference operator[](size_t i) const
-Returns a const reference to the indexed element.
+```
+**Description**  
+Returns a const reference to the indexed element.  
 Undefined behaviour if the string is empty.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 const_reference front() const
+```
+**Description**  
 Returns a const reference to the first element.
 Undefined behaviour if the string is empty.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 const_reference back() const
+```
+**Description**  
 Returns a const reference to the last element.
 Undefined behaviour if the string is empty.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 const_pointer data() const
+```
+**Description**  
 Returns a const pointer to the first element.
 Undefined behaviour if the string is empty.
-____________________________________________________________________________________________________
-Iterators
 
+## Iterators
+
+```cpp
 const_iterator begin() const
 const_iterator cbegin() const
+```
+**Description**  
 Returns an iterator to the beginning of the string view.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 const_iterator end() const
 const_iterator cend() const
+```
+**Description**  
 Returns an iterator to the end of the string view.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 const_iterator rbegin() const
 const_iterator crbegin() const
+```
+**Description**  
 Returns a reverse iterator to the beginning of the string view.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 const_iterator rend() const
 const_iterator crend() const
+```
+**Description**  
 Returns a reverse iterator to the end of the string view.
-____________________________________________________________________________________________________
-Operations
 
+## Operations
+
+```cpp
 size_t copy(T* destination, size_t count, size_t position = 0) const
+```
+**Description**  
 Copies the sub-string at position for count characters or size() - count, whichever smaller,  to the string pointed to by destination.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 basic_string_view substr(size_t position = 0, size_t count = npos) const
+```
+**Description**  
 Returns a view which is the sub-string at position for count characters or size() - count, whichever smaller.
-____________________________________________________________________________________________________
-Capacity
 
+## Capacity
+
+```cpp
 bool empty() const
+```
+**Description**  
 Returns true if the size of the string view is zero, otherwise false.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 size_t size() const
+```
+**Description**  
 Returns the size of the view.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 size_t length() const
+```
+**Description**  
 Alternative for size().
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 size_t max_size() const
+```
+**Description**  
 Returns the maximum possible size of the view.
-____________________________________________________________________________________________________
-Compare
 
+## Compare
+
+```cpp
 int compare(basic_string_view v) const
 int compare(size_t position1, size_t count1, basic_string_view view) const
 int compare(size_t position1, size_t count1, 
@@ -163,86 +256,138 @@ int compare(size_t position1, size_t count1,
 int compare(const T* text) const
 int compare(size_t position1, size_t count, const T* text) const
 int compare(size_t position1, size_t count1, const T* text, size_t count2) const
+```
+**Description**  
 Compares two character sequences.
-____________________________________________________________________________________________________
-Search
 
+## Search
+
+```cpp
 bool starts_with(etl::basic_string_view view) const
 bool starts_with(T x) const
 bool starts_with(const T* x) const
+```
+**Description**  
 Checks if the string view begins with the given prefix.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 bool ends_with(etl::basic_string_view view) const
 bool ends_with(T x) const
 bool ends_with(const T* x) const
+```
+**Description**  
 Checks if the string view ends with the given prefix.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 size_t find(basic_string_view view, size_type position = 0) const
 size_t find(T c, size_t position = 0) const
 size_t find(const T* text, size_t position, size_t count) const
 size_t find(const T* text, size_t position = 0) const;
+```
+**Description**  
 Finds the first sub-string equal to the given character sequence.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 size_t rfind(basic_string_view view, size_t position = npos) const
 size_t rfind(T c, size_t position = npos) const
 size_t rfind(const T* text, size_t position, size_t count) const
 size_t rfind(const T* text, size_t position = npos) const
+```
+**Description**  
 Finds the last sub-string equal to the given character sequence.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 size_t find_first_of(basic_string_view view, size_t position = 0) const
 size_t find_first_of(T c, size_t position = 0) const
 size_t find_first_of(const T* text, size_t position, size_t count) const
 size_t find_first_of(const T* text, size_t position = 0) const
+```
+**Description**  
 Finds the first character equal to any of the characters in the given character sequence.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 size_t find_last_of(basic_string_view view, size_t position = npos) const
 size_t find_last_of(T c, size_t position = npos) const
 size_t find_last_of(const T* text, size_t position, size_type count) const
 size_t find_last_of(const T* text, size_t position = npos) const
+```
+**Description**  
 Finds the last character equal to any of the characters in the given character sequence.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 size_t find_first_not_of(basic_string_view view, size_t position = 0) const
 size_t find_first_not_of(T c, size_t position = 0) const
 size_t find_first_not_of(const T* text, size_t position, size_t count) const
 size_t find_first_not_of(const T* text, size_t position = 0) const
+```
+**Description**  
 Finds the first character not equal to any of the characters in the given character sequence.
-____________________________________________________________________________________________________
 
+---
+
+```cpp
 size_t find_last_not_of(basic_string_view view, size_t position = npos) const
 size_t find_last_not_of(T c, size_t position = npos) const
 size_t find_last_not_of(const T* text, size_t position, size_t count) const
 size_t find_last_not_of(const T* text, size_t position = npos) const
+```
+**Description**  
 Finds the first character not equal to any of the characters in the given character sequence.
-____________________________________________________________________________________________________
-Non-member functions
-Lexicographically comparisons
 
-== true if the contents of the string views are equal, otherwise false.
-!= true if the contents of the string views are not equal, otherwise false.
-<  true if the contents of the lhs are lexicographically less than the contents of the rhs,  otherwise false.
-<= true if the contents of the lhs are lexicographically less than or equal to the contents of the rhs, otherwise false.
->  true if the contents of the lhs are lexicographically greater than the contents of the rhs,  otherwise false.
->= true if the contents of the lhs are lexicographically greater than or equal to the contents of the rhs, otherwise false
+## Non-member functions
+**Lexicographically comparisons**  
 
+`==` `true` if the contents of the string views are equal,  
+otherwise `false`.  
+
+`!=` `true` if the contents of the string views are not equal,  
+otherwise `false`.  
+
+`< ` `true` if the contents of the lhs are lexicographically less than the contents of the rhs,  
+otherwise `false`.  
+
+`<=` `true` if the contents of the lhs are lexicographically less than or equal to the contents of the rhs,  
+otherwise `false`.  
+
+`> ` `true` if the contents of the lhs are lexicographically greater than the contents of the rhs,  
+otherwise `false`.  
+
+`>=` `true` if the contents of the lhs are lexicographically greater than or equal to the contents of the rhs,  
+otherwise `false`.  
+
+---
+
+```cpp
 void swap(etl::basic_string_view<T, TTraits> lhs,
           etl::basic_string_view<T, TTraits> rhs)
+```
 Swaps two views.
-____________________________________________________________________________________________________
-Hash
 
+## Hash
+
+```cpp
 etl::hash<etl::string_view>
 etl::hash<etl::wstring_view>
+etl::hash<etl::u8string_view>
 etl::hash<etl::u16string_view>
 etl::hash<etl::u32string_view>
-____________________________________________________________________________________________________
-Example
+---
 
+**Example**  
+
+```cpp
 etl::string<10> greeting("Hello World");
 
 using View = etl::string_view;
@@ -257,4 +402,4 @@ void Print(const View& view)
 Print(view); // Prints "llo Wo"
 
 size_t hashvalue = etl::hash<View>()(view);
-
+```

docs/strings/to_arithmetic.md

@@ -1,220 +1,340 @@
-to_arithmetic
+---
+title: "to_arithmetic"
+---
 
-Functions that will convert a text representation of an arithmetic type to a value.
-Converts from binary, octal, decimal and hex integrals, and decimal floating point types.
-Supports conversion from char, wchar_t, char16_t and char32_t strings.
-The numeric strings must not contain leading or trailing non-numeric characters. It is the responsibility of the user to select the valid character range.
-Integral types may be constexpr.
-____________________________________________________________________________________________________
-to_arithmetic_status
-An ETL enum type that defines the following enumeration values.
-The are the values that may be set as the error code in to_arithmetic_result.
+{{< callout type="info">}}
+  Header: `to_arithmetic.h`  
+{{< /callout >}}
 
+Functions that will convert a text representation of an arithmetic type to a value.  
+Converts from binary, octal, decimal and hex integrals, and decimal floating point types.  
+Supports conversion from `char`, `wchar_t`, `char8_t`, `char16_t`, and `char32_t` strings.  
+The numeric strings must not contain leading or trailing non-numeric characters. It is the responsibility of the user to select the valid character range.  
+Integral types may be `constexpr`.  
+
+## to_arithmetic_status
+An ETL enum type that defines the following enumeration values.  
+The are the values that may be set as the error code in to_arithmetic_result.  
+
+```cpp
 Valid
 Invalid_Radix
 Invalid_Format
 Invalid_Float
 Signed_To_Unsigned
 Overflow
-____________________________________________________________________________________________________
-to_arithmetic_result
-The result type returned from etl::to_arithmetic.
+```
 
+## to_arithmetic_result
+The result type returned from `etl::to_arithmetic`.
+
+```cpp
 template <typename TValue>
 to_arithmetic_result
-____________________________________________________________________________________________________
-Types    
+```
+
+**Types**  
+```cpp
 value_type      TValue
 error_type      etl::to_arithmetic_status
 unexpected_type etl::unexpected<etl::to_arithmetic_status>
-____________________________________________________________________________________________________
+```
+
+---
+
+```cpp
 ETL_CONSTEXPR14
 to_arithmetic_result()
+```
 Default constructor.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 ETL_CONSTEXPR14
 to_arithmetic_result(const to_arithmetic_result& other)
+```
 Copy constructor.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 ETL_NODISCARD
 ETL_CONSTEXPR14
 bool has_value() const
-Returns true if the result has a valid value.
-If false then the value is undefined.
-____________________________________________________________________________________________________
+```
+Returns `true` if the result has a valid value.  
+If `false` then the value is undefined.
+
+---
+
+```cpp
 ETL_NODISCARD
 ETL_CONSTEXPR14
 operator bool() const
-Returns true if the result has a valid value.
-If false then the value is undefined.
-____________________________________________________________________________________________________
+```
+Returns `true` if the result has a valid value.  
+If `false` then the value is undefined.
+
+---
+
+```cpp
 ETL_NODISCARD
 ETL_CONSTEXPR14
 value_type value() const
-Returns the value, if valid.
+```
+Returns the value, if valid.  
 Otherwise undefined.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 ETL_NODISCARD
 ETL_CONSTEXPR14
 operator value_type() const
-Returns the value, if valid.
+```
+Returns the value, if valid.  
 Otherwise undefined.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 ETL_NODISCARD
 ETL_CONSTEXPR14
 error_type error() const
-Returns the conversion status.
-One of the following:-
+```
+Returns the conversion status.  
+One of the following:-  
+```cpp
 Valid
 Invalid_Radix
 Invalid_Format
 Invalid_Float
 Signed_To_Unsigned
 Overflow
-____________________________________________________________________________________________________
+```
+
+---
+
+```cpp
 ETL_CONSTEXPR14
 to_arithmetic_result& operator =(value_type value)
+```
 Assign from a value_type.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 ETL_CONSTEXPR14
 to_arithmetic_result& operator =(unexpected_type status)
+```
 Assign from an unexpected_type.
-____________________________________________________________________________________________________
-to_arithmetic
-Convert a string to an integral or floating point value.
-Supports: 
-etl::string_view (etl::basic_string_view<TChar>)
-const pointer (to char, wchar_t, char16_t, char32_t) + length
-etl::string, etl::wstring, etl::u16string or etl::u32string
 
+---
+
+## to_arithmetic
+Convert a string to an integral or floating point value.  
+Supports:  
+`etl::string_view` (`etl::basic_string_view<TChar>`)
+const pointer (to `char`, `wchar_t`, `char8_t`, `char16_t`, `char32_t`) + length  
+`etl::string`, `etl::wstring`, `etl::u8string`, `etl::u16string`, or `etl::u32string`.  
+
+```cpp
 template <typename TValue, typename TChar>
 ETL_NODISCARD
 ETL_CONSTEXPR14
 etl::to_arithmetic_result<TValue> to_arithmetic(const etl::basic_string_view<TChar>& view)
+```
 Text to integral or floating point from view and default decimal radix.
-____________________________________________________________________________________________________
-template <typename TValue, typename TChar>
+
+---
+
+```cpp
 template <typename TValue, typename TChar>
 ETL_NODISCARD
 ETL_CONSTEXPR14
 etl::to_arithmetic_result<TValue> to_arithmetic(etl::basic_string_view<TChar> view,
                                                 const etl::radix::value_type  radix)
-Text to integral from view and radix value type.
-radix may be one of the following:-
+```
+Text to integral from view and radix value type.  
+radix may be one of the following:-  
+```cpp
 etl::radix::binary
 etl::radix::octal
 etl::radix::decimal
 etl::radix::hex
-____________________________________________________________________________________________________
+```
+
+---
+
+```cpp
 ETL_NODISCARD
 ETL_CONSTEXPR14
 etl::to_arithmetic_result<TValue> to_arithmetic(const etl::basic_string_view<TChar>& view, 
                                                 const etl::private_basic_format_spec::base_spec& spec)
-Text to integral from view and radix format spec.
-spec may be one of the following:-
+```
+Text to integral from view and radix format spec.  
+spec may be one of the following:-  
+```cpp
 etl::bin
 etl::oct
 etl::dec
 etl::hex
-____________________________________________________________________________________________________
+```
+
+---
+
+```cpp
 template <typename TValue, typename TChar>
 ETL_NODISCARD
 ETL_CONSTEXPR14
 etl::to_arithmetic_result<TValue> to_arithmetic(const TChar* cp, 
                                                 size_t length)
+```
 Text to integral or floating point from pointer, length and default decimal radix.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 template <typename TValue, typename TChar>
 ETL_NODISCARD
 ETL_CONSTEXPR14
 etl::to_arithmetic_result<TValue> to_arithmetic(const TChar* cp, 
                                                 size_t length, 
                                                 const etl::radix::value_type radix)
-Text to integral from pointer, length and radix value type.
-radix may be one of the following:-
+```
+Text to integral from pointer, length and radix value type.  
+radix may be one of the following:-  
+```cpp
 etl::radix::binary
 etl::radix::octal
 etl::radix::decimal
 etl::radix::hex
-____________________________________________________________________________________________________
+```
+
+---
+
+```cpp
 template <typename TValue, typename TChar>
 ETL_NODISCARD
 ETL_CONSTEXPR14
 etl::to_arithmetic_result<TValue> to_arithmetic(const TChar* cp, 
                                                 size_t length, 
                                                 const etl::private_basic_format_spec::base_spec& spec)
-Text to integral from pointer, length and radix format spec.
-spec may be one of the following:-
+```
+Text to integral from pointer, length and radix format spec.  
+spec may be one of the following:-  
+```cpp
 etl::bin
 etl::oct
 etl::dec
 etl::hex
-____________________________________________________________________________________________________
+```
+
+---
+
+```cpp
 template <typename TValue, typename TChar>
 ETL_NODISCARD
 ETL_CONSTEXPR14
 etl::to_arithmetic_result<TValue> to_arithmetic(const etl::ibasic_string<TChar>& str)
+```
 Text to integral or floating point from string and default decimal radix.
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 template <typename TValue, typename TChar>
 ETL_NODISCARD
 ETL_CONSTEXPR14
 etl::to_arithmetic_result<TValue> to_arithmetic(const etl::ibasic_string<TChar>& str, 
                                                 const etl::radix::value_type radix)
-Text to integral from string and radix value type.
-radix may be one of the following:-
+```
+Text to integral from string and radix value type.  
+radix may be one of the following:-  
+```cpp
 etl::radix::binary
 etl::radix::octal
 etl::radix::decimal
 etl::radix::hex
-____________________________________________________________________________________________________
+```
+
+---
+
+```cpp
 template <typename TValue, typename TChar>
 ETL_NODISCARD
 ETL_CONSTEXPR14
 etl::to_arithmetic_result<TValue> to_arithmetic(const etl::ibasic_string<TChar>& str, 
                                                 const etl::private_basic_format_spec::base_spec& spec)
-Text to integral from string and radix format spec.
-spec may be one of the following:-
+```
+Text to integral from string and radix format spec.  
+spec may be one of the following:-  
+```cpp
 etl::bin
 etl::oct
 etl::dec
 etl::hex
-____________________________________________________________________________________________________
-Non-member functions
+```
 
+## Non-member functions
+
+```cpp
 template <typename T>
 ETL_CONSTEXPR14 bool operator ==(const etl::to_arithmetic_result<T>& lhs, 
                                  const etl::to_arithmetic_result<T>& rhs)
+```
 Equality test for etl::to_arithmetic_result
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 template <typename T, typename U>
 ETL_CONSTEXPR14 bool operator ==(const etl::to_arithmetic_result<T>& lhs, 
                                  const U& rhs)
+```
 Equality test for etl::to_arithmetic_result
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 template <typename T, typename U>
 ETL_CONSTEXPR14 bool operator ==(const T& lhs, 
                                  const etl::to_arithmetic_result<U>& rhs)
+```
 Equality test for etl::to_arithmetic_result
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 template <typename T>
 ETL_CONSTEXPR14 bool operator !=(const etl::to_arithmetic_result<T>& lhs, 
                                  const etl::to_arithmetic_result<T>& rhs)
+```
 Inequality test for etl::to_arithmetic_result
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 template <typename T, typename U>
 ETL_CONSTEXPR14 bool operator !=(const etl::to_arithmetic_result<T>& lhs, 
                                  const U& rhs)
+```
 Inequality test for etl::to_arithmetic_result
-____________________________________________________________________________________________________
+
+---
+
+```cpp
 template <typename T, typename U>
 ETL_CONSTEXPR14 bool operator !=(const T& lhs, 
                                  const etl::to_arithmetic_result<T>& rhs)
+```
 Inequality test for etl::to_arithmetic_result
-____________________________________________________________________________________________________
-Examples
 
-Valid conversions
+## Examples
+
+**Valid conversions**  
+```cpp
 const char* BinaryText("1010011");
 const etl::string<3> OctalText("123");
 const etl::string<4> DecimalText(" 83 ");
@@ -233,8 +353,11 @@ int v3 = etl::to_arithmetic<int>(view);
 
 // From hex string. Base 16 radix.
 int v4 = etl::to_arithmetic<int>(HexText, 16);
-____________________________________________________________________________________________________
-Invalid conversions
+```
+---
+
+**Invalid conversions**  
+```cpp
 const etl::string<10> Text1("abcd");
 const etl::string<10> Text2(" 83 ");
 const etl::string<10> Text3("-83");
@@ -254,5 +377,4 @@ result = etl::to_arithmetic<uint32_t>(Text3);   // etl::to_arithmetic_status::Si
 result = etl::to_arithmetic<int32_t>(Text4);    // etl::to_arithmetic_status::Overflow
 
 result = etl::to_arithmetic<float>(Text5);      // etl::to_arithmetic_status::Overflow
-
-
+```

docs/strings/to_string.md

@@ -1,58 +1,77 @@
-to_string
+---
+title: "to_string"
+---
 
-Functions that will render a text representation of bools, integrals, floating point, strings, string views and pointers.
-Uses etl::basic_format_spec to define the required formatting.
+{{< callout type="info">}}
+  Header: `to_string.h`  
+{{< /callout >}}
 
-It will convert to any of the ETL string types.
-____________________________________________________________________________________________________
+Functions that will render a text representation of bools, integrals, floating point, strings, string views and pointers.  
+Uses `etl::basic_format_spec` to define the required formatting.  
 
-Default format specification
-Where StringType is etl::istring, etl::iwstring, etl::iu16string or etl::iu32string
+It will convert to any of the ETL string types.  
 
+## Default format specification
+Where `StringType` is `etl::istring`, `etl::iwstring`, `etl::iu8string`, `etl::iu16string` or `etl::iu32string`.
+
+```cpp
 template <typename T>
 const StringType& to_string(const T value, 
                             StringType& str, 
                             const bool append = false)
+```
 
-20.17.0
+---
+
+```cpp
 template <typename T> // Where T is an integral
 const StringType& to_string(const T value, 
                             uint32_t denominator_exponent,
                             StringType& str, 
                             const bool append = false)
+```
 
-value   The value to convert to a string.
-str     The string in with to place the rendered text.
-append  If true then appends the text to the current string's content. Default false.
-____________________________________________________________________________________________________
+`value`   The value to convert to a string.  
+`str`     The string in with to place the rendered text.  
+`append`  If true then appends the text to the current string's content. Default `false`.  
+Since: `20.17.0`
 
-Supplied format specification
-Where StringType is etl::istring, etl::iwstring, etl::iu16string or etl::iu32string
-Where FormatType is etl::format_spec, etl::wformat_spec, etl::u16format_spec or etl::u32format_spec
+## Supplied format specification
+Where `StringType` is `etl::istring`, `etl::iwstring`, `etl::iu8string`, `etl::iu16string` or `etl::iu32string`.  
+Where `FormatType` is `etl::format_spec`, `etl::wformat_spec`, `etl::u8format_spec`, `etl::u16format_spec` or `etl::u32format_spec`
 
+```cpp
 template <typename T>
 const StringType& to_string(const T value, 
                             StringType& str, 
                             const FormatType& format, 
                             const bool append = false)
+```
 
-20.17.0
-template <typename T> // Where T is an integral
+---
+
+```cpp
+template <typename T>
 const StringType& to_string(const T value, 
                             uint32_t denominator_exponent,
                             StringType& str,
                             const FormatType& format, 
                             const bool append = false)
+```
 
-value                The value to convert to a string.
-denominator_exponent The exponent of the value that is used to divide the value.
-str                  The string in with to place the rendered text.
-format               The format specification.
-append               If true then appends the text to the current string's content. Default false.
-____________________________________________________________________________________________________
-Examples
+`value`                The value to convert to a string.  
+`denominator_exponent` The exponent of the value that is used to divide the value.  
+`str`                  The string in with to place the rendered text.  
+`format`               The format specification.  
+`append`               If `true` then appends the text to the current string's content. Default `false`.  
+Since: `20.17.0`  
 
-Format as a hex character, minimum fill width of 8, fill with zeros
+---
+
+## Examples
+
+Format as a hex character, minimum fill width of 8, fill with zeros  
+```cpp
 etl::format_spec format;
 
 // Format as a hex character, minimum fill width of 8, fill with zeros.
@@ -62,7 +81,7 @@ etl::string<8> text;
 
 // 'text' is set to "00123456"
 etl::to_string(1193046, text, format);
-____________________________________________________________________________________________________
+---
 Format minimum fill width of 8, fill with space and three decimal digits
 etl::format_spec format;
 
@@ -73,16 +92,16 @@ etl::string<8> text;
 
 // 'text' is set to "   3.142"
 etl::to_string(3.1415, text, format); 
-____________________________________________________________________________________________________
+---
 Format a floating point number
 etl::string<19> text = "The result is ";
 
 etl::to_string(3.1415, text, etl::format_spec().precision(3), true);
 // 'text' is set to "The result is 3.142"
-____________________________________________________________________________________________________
+---
 Format an integral number and divide by 10000
 etl::string<19> text = "The result is ";
 
 etl::to_string(31415, 4U, text, etl::format_spec().precision(3), true);
 // 'text' is set to "The result is 3.142"
-
+```

hugo/assets/css/custom.css

@@ -10,10 +10,9 @@ html:not(.dark) .highlight .chroma .cpf {
 }
 
 html:not(.dark) h1 { 
-  color: coral !important;
+  color: white !important;
   width: 100%;
-  background-color: rgb(246, 246, 246) !important;
-  border: black solid 3px !important;
+  background-color: royalblue !important;
   padding: 0.5rem 0.5rem !important;
 }
 
@@ -118,10 +117,10 @@ html.dark .hx\:dark\:bg-dark {
 
 html.dark h1 
 { 
-  color: coral !important;
+  color: white !important;
   width: 100%;
-  background-color: rgb(50, 50, 50) !important;
-  border: lightgrey solid 2px !important;
+  #background-color: rgb(50, 50, 50) !important;
+  background-color: #7099c7 !important;
   padding: 0.5rem 0.5rem !important;
 }
 
@@ -296,9 +295,10 @@ h1 {
   font-family: Roboto, sans-serif !important;
   font-style: i !important;
   font-weight: 500 !important;
+  font-size: 180% !important;
   margin-top: 0.5em !important;
   margin-bottom: 0.0em !important;
-  border-radius: 0.75rem !important;
+  border-radius: 0.5rem !important;
 }
 
 h2 {