wstring_view vs string_view

std::wstring_view and std::string_view are similar types in C++, both introduced to provide a lightweight, read-only view of a string.

The primary difference between the two lies in the type of characters they handle.

• std::string_view is an alias for std::basic_string_view<char>. It works with narrow (8-bit) character strings.
• std::wstring_view is an alias for std::basic_string_view<wchar_t>. It works with wide (typically 16-bit or 32-bit) character strings.

Here's a simple comparison:

1#include <iostream>
2#include <string_view>
3#include <string>
4#include <cwchar>
5
6int main() {
7  std::string_view sv{"Hello, world"};
8  std::wstring_view wsv{L"Hello, wide world"};
9
10  std::cout << sv << '\n';
11  std::wcout << wsv;
12}

1Hello, world
2Hello, wide world

Use std::wstring_view when you are dealing with wide-character strings, which are often used for Unicode or platform-specific text representations requiring more than one byte per character.

In contrast, std::string_view is used for narrow-character strings, which are more common in ASCII or UTF-8 encoded text.

Choosing between these types depends on the nature of the text data you are handling. For most internationalized applications, std::wstring_view can be essential for proper character representation and manipulation.