C++：关于string转C-风格字符串

std::basic_string::c_str

 

C++

 

Strings library

 

std::basic_string

 

const CharT* c_str() const;

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)

这里：

用c_str() 方法可以返回一个指向C-风格的字符串的指针。

如:

string filename;
cout << "Enter the file name: ":
cin >> filename;
ofstream fout;
fout.open(filename.c_str());