Hi all,
I have a function similar to the following, which returns a string:
std::string foo() {
return <whatever>;
}
..then I want to use its c_str(), say like this (sorry for the silly
example):
int main() {
printf("foo is %s",foo().c_str());
}
Of course, for printf() to work, the temporary object that is returned
by foo() should not be (automatically) destroyed too early, or the
pointer returned by c_str() would not be valid anymore.
So, my question is: *when* is that temporary string created and
destroyed? is it safe to assume that it exists until printf()
returns, and thus that I can use its c_str() this way?
I've always thought that the temporary would be destroyed *before*
calling printf() [ create a string, get the value for c_str(),
destroy the string, invoke printf() ] thus actually passing an
invalid pointer in this case, but to my surprise I put together some
lines and gcc proved me wrong. Is it just gcc? Or is it a standard
C++ behavior?
Thanks,
Andrea.
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