Concatenate string_views
Is it possible to concatenate two std::string_view objects?
Concatenating two std::string_view objects directly is not possible because std::string_view is a non-owning, read-only view of a string.
However, you can achieve concatenation by creating a new std::string that combines the contents of both std::string_view objects.
Here's how you can do it:
#include <iostream>
#include <string>
#include <string_view>
int main() {
std::string_view view1{"Hello, "};
std::string_view view2{"world!"};
// Create a new std::string that
// concatenates view1 and view2
std::string combined{view1};
combined += view2;
std::cout << combined;
}Hello, world!Using std::stringstream
Another approach involves using std::stringstream for concatenation:
#include <iostream>
#include <sstream>
#include <string_view>
int main() {
std::string_view view1{"Hello, "};
std::string_view view2{"world!"};
std::stringstream ss;
ss << view1 << view2;
std::string combined = ss.str();
std::cout << combined;
}Hello, world!Custom Function
For more flexibility, you can write a function to concatenate std::string_view objects:
#include <iostream>
#include <string>
#include <string_view>
std::string concatenate(
std::string_view a, std::string_view b
) {
return std::string{a} + std::string{b};
}
int main() {
std::string_view view1{"Hello, "};
std::string_view view2{"world!"};
std::string combined =
concatenate(view1, view2);
std::cout << combined;
}Hello, world!While std::string_view itself doesn't support concatenation, combining them into a new std::string is straightforward and provides the desired result.
String Views
A practical introduction to string views, and why they should be the main way we pass strings to functions