std::basic_string<CharT,Traits,Allocator>::capacity (3) - Linux Manuals

std::basic_string<CharT,Traits,Allocator>::capacity: std::basic_string<CharT,Traits,Allocator>::capacity

NAME

std::basic_string<CharT,Traits,Allocator>::capacity - std::basic_string<CharT,Traits,Allocator>::capacity

Synopsis

size_type capacity() const; (until C++11)
size_type capacity() const noexcept; (since C++11)

Returns the number of characters that the string has currently allocated space for.

Parameters

(none)

Return value

Capacity of the currently allocated storage

Complexity

Constant

Example

// Run this code

  #include <iostream>
  #include <string>

  void show_capacity(std::string const& s)
  {
      std::cout << "'" << s << "' has capacity " << s.capacity() << ".\n";
  }

  int main()
  {
      std::string s{"Exemplar"};
      show_capacity(s);

      s += " is an example string.";
      show_capacity(s);
  }

Possible output:

  'Exemplar' has capacity 15.
  'Exemplar is an example string.' has capacity 30.