deduction guides for std::forward_list

 

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array (C++11)

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forward_list (C++11)

list

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unordered_set (C++11)

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std::forward_list

Member functions

forward_list::forward_list

forward_list::~forward_list

forward_list::operator=

forward_list::assign

forward_list::get_allocator

Element access

forward_list::front

Iterators

forward_list::before_beginforward_list::cbefore_begin

forward_list::beginforward_list::cbegin

forward_list::endforward_list::cend

Capacity

forward_list::empty

forward_list::max_size

Modifiers

forward_list::clear

forward_list::insert_after

forward_list::emplace_after

forward_list::erase_after

forward_list::push_front

forward_list::emplace_front

forward_list::pop_front

forward_list::resize

forward_list::swap

Operations

forward_list::merge

forward_list::splice_after

forward_list::removeforward_list::remove_if

forward_list::reverse

forward_list::unique

forward_list::sort

Non-member functions

std::swap

eraseerase_if (C++20)(C++20)

operator==operator!=operator<operator>operator<=operator>=operator<=> (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20)

Deduction guides(C++17)

 

Defined in header <forward_list>
template< class InputIt,           class Alloc = std::allocator<typename std::iterator_traits<InputIt>::value_type>> forward_list(InputIt, InputIt, Alloc = Alloc())   -> forward_list<typename std::iterator_traits<InputIt>::value_type, Alloc>;		(since C++17)

This deduction guide is provided for forward_list to allow deduction from an iterator range. This overload participates in overload resolution only if InputIt satisfies LegacyInputIterator and Alloc satisfies Allocator.

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

Run this code

#include <forward_list>
#include <vector>
int main() {
   std::vector<int> v = {1, 2, 3, 4};
 
   // uses explicit deduction guide to deduce std::forward_list<int>
   std::forward_list x(v.begin(), v.end()); 
 
   // deduces std::forward_list<std::vector<int>::iterator>
   // first phase of overload resolution for list-initialization selects the candidate
   // synthesized from the initializer-list constructor; second phase is not performed and
   // deduction guide has no effect
   std::forward_list y{v.begin(), v.end()}; 
}