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 fromc_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, excludingoperator[],at(),front(),back(),begin(),rbegin(),end() andrend()(since C++11).

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

[edit]Parameters

(none)

[edit]Return value

Pointer to the underlying character storage.

[edit]Complexity

Constant.

[edit]Notes

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

[edit]Example

#include <algorithm>#include <cassert>#include <cstring>#include <string> extern"C"void c_func(constchar* c_str){    printf("c_func called with '%s'\n", c_str);} int main(){std::stringconst s("Emplary");constchar* p= s.c_str();assert(s.size()==std::strlen(p));assert(std::equal(s.begin(), s.end(), p));assert(std::equal(p, p+ s.size(), s.begin()));assert('\0'==*(p+ s.size()));     c_func(s.c_str());}

c_func called with 'Emplary'

[edit]See also

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