deduction guides for std::
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template< class InputIt, class Alloc = std::allocator<typename std::iterator_traits<InputIt>::value_type>> |
(since C++17) | |
This deduction guide is provided for to allow deduction from an iterator range. This overload participates in overload resolution only if InputIt
satisfies Template:concept and Alloc
satisfies Template:concept
Note: the extent to which the library determines that a type does not satisfy LegacyInputIterator is unspecified, except that as a minimum integral types do not qualify as input iterators. Likewise, the extent to which it determines that a type does not satisfy Allocator is unspecified, except that as a minimum the member type Alloc::value_type
must exist and the expression std::declval<Alloc&>().allocate(std::size_t{}) must be well-formed when treated as an unevaluated operand.
Example
#include <{{{1}}}> #include <vector> int main() { std::vector<int> v = {1, 2, 3, 4}; std:: x(v.begin(), v.end()); // uses explicit deduction guide }