std::convertible_to

Defined in header <concepts>
template < class From, class To > concept convertible_to = std::is_convertible_v <From, To> &&     requires { static_cast <To> ( std::declval <From> ( ) ) ; } ;		(since C++20)

The concept convertible_to<From, To> specifies that an expression of the same type and value category as those of std::declval <From> ( ) can be implicitly and explicitly converted to the type To

Semantic requirements

convertible_to<From, To> is modeled only if, given a function fun of type std::add_rvalue_reference_t <From> ( ) such that the expression fun() is equality-preserving

• Either
  • To is neither an object type nor a reference-to-object type, or
  • static_cast<To>(fun()) is equal to [ ] ( ) - > To { return fun( ) ; } ( )

• One of the following is true:
  • std::add_rvalue_reference_t<From>
  • std::add_rvalue_reference_t<From> is an rvalue reference to a non-const-qualified type, and the resulting state of the object referenced by fun()
  • the object referred to by fun() is not modified by either expression above.

Equality preservation

Expressions declared in requires expressions of the standard library concepts are required to be equality-preserving

References

See also

is_convertibleis_nothrow_convertible (C++11)(C++20)

checks if a type can be converted to the other type (class template)