std::basic_string<CharT,Traits,Allocator>::c_str (3) - Linux Man Pages

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

NAME

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

Synopsis


const CharT* c_str() const; (until C++11)
const CharT* c_str() const noexcept; (since C++11)


Returns a pointer to a null-terminated character array with data equivalent to those stored in the string.
The pointer is such that the range [c_str(); c_str() + size()] is valid and the values in it correspond to the values stored in the string with an additional null character after the last position.
The pointer obtained from c_str() may be invalidated by:


* Passing a non-const reference to the string to any standard library function, or
* Calling non-const member functions on the string, excluding operator[], at(), front(), back(), begin(), rbegin(), end() and rend().


Writing to the character array accessed through c_str() is undefined behavior.


c_str() and data() perform the same function. (since C++11)

Parameters


(none)

Return value


Pointer to the underlying character storage.


c_str()[i] == operator[](i) for every i in [0, size()). (until C++11)
c_str() + i == std::addressof(operator[](i)) for every i in [0, size()]. (since C++11)

Complexity


Constant.

Notes


The pointer obtained from c_str() may only be treated as a pointer to a null-terminated character string if the string object does not contain other null characters.

Example


// Run this code


  #include <algorithm>
  #include <cassert>
  #include <cstring>
  #include <string>


  int main()
  {
    std::string const s("Emplary");
    assert(s.size() == std::strlen(s.c_str()));
    assert(std::equal(s.begin(), s.end(), s.c_str()));
    assert(std::equal(s.c_str(), s.c_str() + s.size(), s.begin()));
    assert(0 == *(s.c_str() + s.size()));
  }

See also


front accesses the first character
        (public member function)
(C++11)


back accesses the last character
        (public member function)
(C++11)
        returns a pointer to the first character of a string
data (public member function)