In C++, std::experimental::string_view is a non-owning view over a sequence of characters. It provides a read-only view of a contiguous sequence of characters and is particularly useful for passing substrings of strings to functions without the need to create a new string.

Features and Benefits

• Non-owning View: Unlike std::string, std::experimental::string_view does not own the underlying character sequence.
• Cost-effective: Since it doesn’t allocate memory or make any copies, it’s efficient for passing strings to functions and for comparisons.
• Compatibility: It’s compatible with existing code that accepts std::string and provides a safer, more efficient alternative to pointer/length pairs.

Usage

Creating std::experimental::string_view

You can create a std::experimental::string_view from a const char* or a std::string:

std::string_view view1 = "Hello, World!";
std::string_view view2 = std::string("Hello, C++");

Operations on std::experimental::string_view

• Accessing characters using operator[]
• Obtaining the length using size() or length()
• Substring operations using substr()
• Comparisons using operator== and operator!=

Example

void print_string_view(std::string_view view) {
    for (char c : view) {
        std::cout << c;
    }
}

int main() {
    std::string str = "Hello, C++";
    print_string_view(str);
    return 0;
}

Availability

std::experimental::string_view is available in the C++17 standard. To use it, ensure that you compile with the appropriate version of the C++ standard library that supports C++17.

For more details, refer to the official C++ reference.

Using std::experimental::string_view can improve code efficiency and reduce unnecessary string copies, making it a valuable addition to C++ when working with string views.