mirror of
https://github.com/ETLCPP/etl.git
synced 2026-06-15 08:26:04 +08:00
156 lines
3.6 KiB
Markdown
156 lines
3.6 KiB
Markdown
---
|
|
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.
|
|
From: `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.
|
|
From: `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.
|
|
```
|