deduction guides for std::tuple - cppreference.com (original) (raw)
| Defined in header | ||
|---|---|---|
| template<class... UTypes>tuple(UTypes...) -> tuple<UTypes...>; | (1) | (since C++17) |
| template<class T1, class T2>tuple(std::pair<T1, T2>) -> tuple<T1, T2>; | (2) | (since C++17) |
| template<class Alloc, class... UTypes>tuple(std::allocator_arg_t, Alloc, UTypes...) -> tuple<UTypes...>; | (3) | (since C++17) |
| template<class Alloc, class T1, class T2>tuple(std::allocator_arg_t, Alloc, std::pair<T1, T2>) -> tuple<T1, T2>; | (4) | (since C++17) |
| template<class Alloc, class... UTypes>tuple(std::allocator_arg_t, Alloc, tuple<UTypes...>) -> tuple<UTypes...>; | (5) | (since C++17) |
These deduction guides are provided for std::tuple to account for the edge cases missed by the implicit deduction guides, in particular, non-copyable arguments and array to pointer conversion.
[edit] Example
#include int main() { int a[2], b[3], c[4]; std::tuple t1{a, b, c}; // explicit deduction guide is used in this case }