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      std::queue<T,Container>::queue

      From cppreference.com
      <cpp‎ |container‎ |queue

      [edit template]
       
       
       
       
      queue(): queue(Container()){}
      		 (1)(since C++11)
      (2)
      explicit queue(const Container& cont= Container());
      		(until C++11)
      explicit queue(const Container& cont);
      		(since C++11)
      explicit queue( Container&& cont);
      		 (3)(since C++11)
      queue(const queue& other);
      		 (4)(implicitly declared)
      queue( queue&& other);
      		 (5)(since C++11)
      (implicitly declared)
      template<class InputIt>
      queue( InputIt first, InputIt last);
      		 (6)(since C++23)
      template<class Alloc>
      explicit queue(const Alloc& alloc);
      		 (7)(since C++11)
      template<class Alloc>
      queue(const Container& cont,const Alloc& alloc);
      		 (8)(since C++11)
      template<class Alloc>
      queue( Container&& cont,const Alloc& alloc);
      		 (9)(since C++11)
      template<class Alloc>
      queue(const queue& other,const Alloc& alloc);
      		 (10)(since C++11)
      template<class Alloc>
      queue( queue&& other,const Alloc& alloc);
      		 (11)(since C++11)
      template<class InputIt,class Alloc>
      queue( InputIt first, InputIt last,const Alloc& alloc);
      		 (12)(since C++23)
      template<container-compatible-range<T> R>
      queue(std::from_range_t, R&& rg);
      		 (13)(since C++23)
      template<container-compatible-range<T> R,class Alloc>
      queue(std::from_range_t, R&& rg,const Alloc& alloc);
      		 (14)(since C++23)

      Constructs new underlying container of the container adaptor from a variety of data sources.

      1) Default constructor. Value-initializes the container.
      2) Copy-constructs the underlying containerc with the contents ofcont.This is also the default constructor.(until C++11)
      3) Move-constructs the underlying containerc withstd::move(cont).
      4)Copy constructor. The adaptor is copy-constructed with the contents ofother.c.
      5)Move constructor. The adaptor is constructed withstd::move(other.c).
      6) Constructs the underlying containerc with the contents of the range[first, last). This overload participates in overload resolution only ifInputIt satisfiesLegacyInputIterator.
      7-12) These constructors participate in overload resolution only ifstd::uses_allocator<Container, Alloc>::value istrue, that is, if the underlying container is an allocator-aware container (true for all standard library containers that can be used withqueue).
      7) Constructs the underlying container usingalloc as allocator, as if byc(alloc).
      8) Constructs the underlying container with the contents ofcont and usingalloc as allocator, as if byc(cont, alloc).
      9) Constructs the underlying container with the contents ofcont using move semantics while utilizingalloc as allocator, as if byc(std::move(cont), alloc).
      10) Constructs the adaptor with the contents ofother.c and usingalloc as allocator, as if byc(other.c, alloc).
      11) Constructs the adaptor with the contents ofother using move semantics while utilizingalloc as allocator, as if byc(std::move(other.c), alloc).
      12) Constructs the underlying container with the contents of the range[first, last) usingalloc as allocator, as if byc(first, last, alloc). This overload participates in overload resolution only ifInputIt satisfiesLegacyInputIterator.
      13) Constructs the underlying container withranges::to<Container>(std::forward<R>(rg)).
      14) Constructs the underlying container withranges::to<Container>(std::forward<R>(rg), alloc).

      Contents

      [edit]Parameters

      alloc - allocator to use for all memory allocations of the underlying container
      other - another container adaptor to be used as source to initialize the underlying container
      cont - container to be used as source to initialize the underlying container
      first, last - the pair of iterators defining the sourcerange of elements to initialize with
      rg - acontainer compatible range, that is, aninput_range whose elements are convertible toT
      Type requirements
      -
      Alloc must meet the requirements ofAllocator.
      -
      Container must meet the requirements ofContainer. The constructors taking an allocator parameter participate in overload resolution only ifContainer meets the requirements ofAllocatorAwareContainer.
      -
      InputIt must meet the requirements ofLegacyInputIterator.

      [edit]Complexity

      Same as the corresponding operation on the wrapped container.

      [edit]Notes

      Feature-test macroValueStdFeature
      __cpp_lib_adaptor_iterator_pair_constructor202106L(C++23)Iterator pair constructors forstd::queue andstd::stack; overloads(6) and(12)
      __cpp_lib_containers_ranges202202L(C++23)Ranges-aware construction and insertion; overloads(13) and(14)

      [edit]Example

      Run this code
      #include <cassert>#include <deque>#include <iostream>#include <memory>#include <ranges>#include <queue> int main(){std::queue<int> c1;    c1.push(5);assert(c1.size()==1); std::queue<int> c2(c1);assert(c2.size()==1); std::deque<int> deq{3,1,4,1,5};std::queue<int> c3(deq);// overload (2)assert(c3.size()==5); # ifdef __cpp_lib_adaptor_iterator_pair_constructorconstauto il={2,7,1,8,2};std::queue<int> c4{il.begin(), il.end()};// C++23, (6)assert(c4.size()==5);# endif # if __cpp_lib_containers_ranges >= 202202L// C++23, overload (13)auto c5=std::queue(std::from_range_t, std::ranges::iota(0,42));assert(c5.size()==42); // the same effect with pipe syntax, internally uses overload (13)auto c6= std::ranges::iota(0,42)| std::ranges::to<std::queue>();assert(c6.size()==42); std::allocator<int> alloc; // C++23, overload (14)auto c7=std::queue(std::from_range_t, std::ranges::iota(0,42), alloc);assert(c7.size()==42); // the same effect with pipe syntax, internally uses overload (14)auto c8= std::ranges::iota(0,42)| std::ranges::to<std::queue>(alloc);assert(c8.size()==42);# endif}

      [edit]Defect reports

      The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

      DRApplied toBehavior as publishedCorrect behavior
      P0935R0C++11default constructor was explicitmade implicit

      [edit]See also

      assigns values to the container adaptor
      (public member function)[edit]
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