conditional Class
The latest version of this topic can be found at conditional Class.
Selects one of two types, depending on the specified condition.
Syntax
template <bool B, class T1, class T2>
struct conditional;
template <bool _Test, class _T1, class _T2>
using conditional_t = typename conditional<_Test, _T1, _T2>::type;
Parameters
B
The value that determines the selected type.
T1
The type result when B is true.
T2
The type result when B is false.
Remarks
The template member typedef conditional<B, T1, T2>::type
evaluates to T1
when B
evaluates to true
, and evaluates to T2
when B
evaluates to false
.
Requirements
Header: <type_traits>
Namespace: std