std::meta::is_swappable_with_type, std::meta::is_swappable_type, std::meta::is_nothrow_swappable_with_type, std::meta::is_nothrow_swappable_type
From cppreference.com
| Defined in header <meta>
|
||
consteval bool is_swappable_with_type( std::meta::info r1,
std::meta::info r2 );
|
(1) | (since C++26) |
consteval bool is_swappable_type( std::meta::info r );
|
(2) | (since C++26) |
consteval bool is_nothrow_swappable_with_type( std::meta::info r1,
std::meta::info r2 );
|
(3) | (since C++26) |
consteval bool is_nothrow_swappable_type( std::meta::info r );
|
(4) | (since C++26) |
Determines if the reflected types T, T1 and T2, represented by r, r1 and r2 respectively, are swappable.
1) Equivalent to
return std::is_swappable_with_v<T1, T2>;.2) Equivalent to
return std::is_swappable_v<T>;.3) Equivalent to
return std::is_nothrow_swappable_with_v<T1, T2>;.4) Equivalent to
return std::is_nothrow_swappable_v<T>;.Parameters
| r, r1, r2 | - | reflection values to test |
Return value
1,3)
true if types T1 and T2 are swappable as described above. Otherwise, false.2,4)
true if type T is swappable as described above. Otherwise, false.Exceptions
Throws std::meta::exception:
- If any of
r,r1, orr2does not represent a type or type alias. - If any of
T,T1, orT2does not represent a complete type, (possibly cv-qualified)void, or an array of unknown bound. - If an instantiation of a template above depends, directly or indirectly, on an incomplete type, and that instantiation could yield a different result if that type were hypothetically completed.
Notes
These functions do not check anything outside the immediate context of the swap expressions: if the use of T1 or T2 would trigger template specializations, generation of implicitly-defined special member functions etc, and those have errors, the actual swap may not compile even if std::is_swappable_with_v<T1, T2> compiles and evaluates to true.
Example
Run this code
#include <meta>
#include <vector>
static_assert
(
is_swappable_type(^^int) and
!is_swappable_with_type(^^int, ^^int) and
is_nothrow_swappable_type(^^int) and
!is_nothrow_swappable_with_type(^^int, ^^int) and
is_swappable_type(^^std::vector<int>) and
!is_swappable_with_type(^^int, ^^float) and
!is_swappable_with_type(^^int, ^^char) and
"");
int main() {}