public member function
<initializer_list>

std::initializer_list::size

size_t size() const noexcept;
constexpr size_t size() const noexcept;
Return size of list
Returns the number of elements in the initializer_list.

参数



返回值

The number of elements in the list.

size_t 是一个无符号整数类型。

示例

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// initializer_list::size
#include <iostream>          // std::cout
#include <initializer_list>  // std::initializer_list

template<class T> struct simple_container {
  T * data;
  unsigned n;
  simple_container(std::initializer_list<int> args) {
    data = new T [args.size()];
    n=0;
    for (T x : args) {data[n++]=x;}
  }
  T* begin() {return data;}
  T* end() {return data+n;}
};

int main ()
{
  simple_container<int> myobject {10, 20, 30};
  std::cout << "myobject contains:";
  for (int x : myobject) std::cout << ' ' << x;
  std::cout << '\n';
  return 0;
}

输出
myobject contains: 10 20 30


复杂度

常量。

数据竞争

The object is accessed. All contained elements are constant: Concurrently accessing them is always safe.

异常安全

无异常保证:此成员函数从不抛出异常。

另见