std::basic_string<CharT,Traits,Allocator> str() const; | (1) | |
void str(const std::basic_string<CharT,Traits,Allocator>& new_str); | (2) |
Manages the contents of the underlying string object.
1) Returns a copy of the underlying string as if by calling rdbuf()->str().
2) Replaces the contents of the underlying string as if by calling rdbuf()->str(new_str).
| new_str | - | new contents of the underlying string |
1) a copy of the underlying string object.
2) (none).
The copy of the underlying string returned by str is a temporary object that will be destructed at the end of the expression, so directly calling c_str() on the result of str() (for example in auto *ptr = out.str().c_str();) results in a dangling pointer.
#include <sstream>
#include <iostream>
int main()
{
int n;
std::istringstream in; // could also use in("1 2")
in.str("1 2");
in >> n;
std::cout << "after reading the first int from \"1 2\", the int is "
<< n << ", str() = \"" << in.str() << "\"\n";
std::ostringstream out("1 2");
out << 3;
std::cout << "after writing the int '3' to output stream \"1 2\""
<< ", str() = \"" << out.str() << "\"\n";
std::ostringstream ate("1 2", std::ios_base::ate);
ate << 3;
std::cout << "after writing the int '3' to append stream \"1 2\""
<< ", str() = \"" << ate.str() << "\"\n";
}Output:
after reading the first int from "1 2", the int is 1, str() = "1 2" after writing the int '3' to output stream "1 2", str() = "3 2" after writing the int '3' to append stream "1 2", str() = "1 23"
| replaces or obtains a copy of the associated character string (public member function of std::basic_stringbuf<CharT,Traits,Allocator>) |
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