Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

This is an older version of Boost and was released in 2023. The current version is 1.90.0.

Struct template is_subconcept

Struct template is_subconcept

boost::type_erasure::is_subconcept

Synopsis

// In header: <boost/type_erasure/is_subconcept.hpp>

template<typename Sub, typename Super, typename PlaceholderMap = void> 
struct is_subconcept : public boost::mpl::and_::type {
};

Description

is_subconcept is a boolean metafunction that determines whether one concept is a sub-concept of another.

is_subconcept<incrementable<>, incrementable<> >             -> true
is_subconcept<incrementable<>, addable<> >                   -> false
is_subconcept<incrementable<_a>, forward_iterator<_iter>,
  mpl::map<mpl::pair<_a, _iter> > >                          -> true

Template Parameters

```
typename Sub
```
The sub concept
```
typename Super
```
The super concept
```
typename PlaceholderMap = void
```
(optional) An MPL map with keys for every non-deduced placeholder in Sub. The associated value of each key is the corresponding placeholder in Super. If PlaceholderMap is omitted, Super and Sub are presumed to use the same set of placeholders.