template <class T, class... Args> void emplace(Args&&... args); | (1) | (since C++17) |
template <class T, class U, class... Args> void emplace(std::initializer_list<U> il, Args&&... args); | (2) | (since C++17) |
template <size_t I, class... Args> void emplace(Args&&... args); | (3) | (since C++17) |
template <size_t I, class U, class... Args> void emplace(std::initializer_list<U> il, Args&&... args); | (4) | (since C++17) |
Creates a new value in-place, in an existing variant object.
emplace<I>(std::forward<Args>(args)...), where I is the zero-based index of T in Types.... This overload only participates in overload resolution if std::is_constructible_v<T, Args...> is true, and T occurs exactly once in Types...
emplace<I>(il, std::forward<Args>(args)...), where I is the zero-based index of T in Types.... This overload only participates in overload resolution if std::is_constructible_v<T, std::initializer_list<U>&, Args...> is true, and T occurs exactly once in Types...
T_I with the arguments std::forward<Args>(args).... If an exception is thrown, *this may become valueless_by_exception. This overload only participates in overload resolution if std::is_constructible_v<T_I, Args...> is true. The behavior is undefined if I is not less than sizeof...(Types).T_I with the arguments il, std::forward<Args>(args).... If an exception is thrown, *this may become valueless_by_exception. This overload only participates in overload resolution if std::is_constructible_v<T_I, initializer_list<U>&, Args...> is true. The behavior is undefined if I is not less than sizeof...(Types).| args | - | constructor arguments to use when constructing the new value |
| il | - | initializer_list argument to use when constructing the new value |
(none).
| assigns a variant (public member function) |
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