#include <cstdio>
#include <string>
void fun(const char* c)
{
printf("--> %s\n", c);
}
std::string get()
{
std::string str = "Hello World";
return str;
}
int main()
{
const char *cc = get().c_str();
// cc is not valid at this point. As it is pointing to
// temporary string internal buffer, and the temporary string
// has already been destroyed at this point.
fun(cc);
// But I am surprise this call will yield valid result.
// It seems that the returned temporary string is valid within
// scope (...)
// What my understanding is, scope means {...}
// Is this valid behavior guarantee by C++ standard? Or it depends
// on your compiler vendor implementations?
fun(get().c_str());
getchar();
}
La salida es:Vida Ámbito de variable temporal
-->
--> Hello World
Hola, se puede saber el comportamiento correcto es garantía de C++ estándar, o que depende de sus implementaciones de proveedores compilador? He probado esto en VC2008 y VC6. Funciona bien para ambos.
Duplicado de: http://stackoverflow.com/questions/2506793/c-life-span-of-temporary-arguments –
Por cierto, su función 'get' se puede simplificar a: std :: string get () {return "Hello World"; } – fredoverflow