std :: ostringstream到LPCSTR？

Question

How can I convert a std::ostringstream to LPCSTR ?

std::ostringstream oss;
[...]
LPCSTR result = oss.str();

Result: Error: No suitable conversion function from "std::basic_string<char, std::char_traits<char>, std::allocator<char>>" to "LPCSTR" exists

Answer 1

Like this:

std::string str = oss.str();
LPCSTR cstr = str.c_str();

Note that you cstr only remains valid until the next modification of str . So you cannot, for instance, return cstr from a function because str is a local variable that has left scope.

Instead of returning LPCSTR from this function, return std::string . That avoids dealing with lifetime issues if you returned LPCSTR . If you returned LPCSTR you would have to allocate memory and make sure you deallocated it. Exactly the sort of thing you don't want to be doing in C++ code. So, return std::string and call c_str() on that object at the point where you call the Windows API function.