---
title: "flags"
---

{{< callout type="info">}}
  Header: `flags.h`  
  Since: `TBC`  
{{< /callout >}}

Provides a wrapper around a set of binary flags.  
Supports compile time and runtime variants  

```cpp
template <typename T, T MASK = etl::integral_limits<T>::max>
class flags
```
`T` must be an unsigned integral type.  
`MASK` is used to exclude unused or undefine bits from operations of the flags. By default, all bits are included.  

Most member functions may be chained.  
```cpp
bool isF5Set = flags.set(bitPattern, true).flip().test(F5);
```

## Constructor
```cpp
ETL_CONSTEXPR flags() ETL_NOEXCEPT
```
**Description**
Constructs a flag set with all elements set to `0` (`false`).

---

```cpp
ETL_CONSTEXPR flags(value_type pattern) ETL_NOEXCEPT
```
**Description**
Constructs a flag set with elements set to pattern.

---

```cpp
ETL_CONSTEXPR flags(const flags<T, MASK>& pattern) ETL_NOEXCEPT
```
**Description**
Constructs a flag set with elements set to pattern.

## Modifiers

```cpp
ETL_CONSTEXPR14 flags<T, MASK>& operator =(flags<T, MASK> other) ETL_NOEXCEPT
```
**Description**
Assigns from another flags object.

---

```cpp
ETL_CONSTEXPR14 flags<T, MASK>& operator =(value_type pattern) ETL_NOEXCEPT
```
**Description**
Assigns from a bit pattern.

---

```cpp
template <value_type pattern, bool value>
ETL_CONSTEXPR14 flags<T, MASK>& set() ETL_NOEXCEPT
```

---

```cpp
template <value_type pattern>
ETL_CONSTEXPR14 flags<T, MASK>& set(bool value) ETL_NOEXCEPT
```

---

```cpp
template <value_type pattern>
ETL_CONSTEXPR14 flags<T, MASK>& set() ETL_NOEXCEPT
```

---

```cpp
ETL_CONSTEXPR14 flags<T, MASK>& set(value_type pattern) ETL_NOEXCEPT
```

---

```cpp
ETL_CONSTEXPR14 flags<T, MASK>& set(value_type pattern, bool value) ETL_NOEXCEPT
```

---

```cpp
ETL_CONSTEXPR14 flags<T, MASK>& clear() ETL_NOEXCEPT
```
____________________________________________________________________________________________________
template <value_type pattern>
ETL_CONSTEXPR14 flags<T, MASK>& reset() ETL_NOEXCEPT
____________________________________________________________________________________________________
ETL_CONSTEXPR14 flags<T, MASK>& reset(value_type pattern) ETL_NOEXCEPT
____________________________________________________________________________________________________
ETL_CONSTEXPR14 flags<T, MASK>& flip() ETL_NOEXCEPT
____________________________________________________________________________________________________
template <value_type pattern>
ETL_CONSTEXPR14 flags<T, MASK>& flip() ETL_NOEXCEPT
____________________________________________________________________________________________________
ETL_CONSTEXPR14 flags<T, MASK>& flip(value_type pattern) ETL_NOEXCEPT
____________________________________________________________________________________________________
Access

template <value_type pattern>
ETL_CONSTEXPR bool test() const ETL_NOEXCEPT
Test the bits for the compile time pattern.
____________________________________________________________________________________________________
ETL_CONSTEXPR bool test(value_type pattern) const ETL_NOEXCEPT
Test the bits for the run time pattern.
____________________________________________________________________________________________________
ETL_CONSTEXPR value_type value() const ETL_NOEXCEPT
ETL_CONSTEXPR operator value_type() const ETL_NOEXCEPT
Returns the value of the flags as a value_type.
____________________________________________________________________________________________________
Operations

____________________________________________________________________________________________________
Non-member functions

template <typename T, T MASK>
void swap(flags<T, MASK>& lhs, flags<T, MASK>& rhs)
Swaps two flags.

template <typename T, T MASK>
bool operator == (flags<T, MASK>& lhs, flags<T, MASK>& rhs)
Checks equality of two flags.

template <typename T, T MASK>
bool operator != (flags<T, MASK>& lhs, flags<T, MASK>& rhs)
Checks inequality of two flags.