std::variant<Types...>::~variant
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std::variant
variant::~variant
(C++26)
~variant();
(since C++17) (constexpr since C++20)
If valueless_by_exception() is true, does nothing. Otherwise, destroys the currently contained object.
This destructor is trivial if std::is_trivially_destructible_v <T_i> is true for all T_i in Types....
[edit] Notes
| Feature-test macro | Value | Std | Feature |
|---|---|---|---|
__cpp_lib_variant |
202106L |
(C++20) (DR) |
Fully constexpr std::variant
|
[edit] Example
Run this code
#include <cstdio> #include <variant> int main() { struct X { ~X() { puts("X::~X();"); } }; struct Y { ~Y() { puts("Y::~Y();"); } }; { puts("entering block #1"); std::variant <X,Y> var; puts("leaving block #1"); } { puts("entering block #2"); std::variant <X,Y> var{ std::in_place_index_t <1>{} }; // constructs var(Y) puts("leaving block #2"); } }
Output:
entering block #1 leaving block #1 X::~X(); entering block #2 leaving block #2 Y::~Y();
[edit] Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| P2231R1 | C++20 | the destructor was not constexpr while non-trivial destructors can be constexpr in C++20 | made constexpr |