How to use std::wstring and std::wstring_convert (C++17 or later) In C++
Starting from C++17, the <string> header introduced new overloads of std::string constructors and member functions that accept wide-character string inputs. Combined with std::wstring_convert, this provides an alternative approach.
Example
- The code demonstrates an alternative approach to convert a wide-character string to a std::string using the wstring_convert class template and the codecvt_utf8_utf16 codecvt facet.
- Instead of creating a std::wstring object separately, it directly converts the LPCWSTR to a std::string by constructing a temporary wstring object within the converter.to_bytes function call.
- This saves a step in the conversion process.
Implementation:
C++
#include <codecvt> #include <iostream> #include <locale> #include <string> #include <windows.h> using namespace std; // Function to convert LPCWSTR to std::string string ConvertLPCWSTRToString(LPCWSTR lpcwszStr) { // Create a converter object to convert between wide // strings and UTF-8 encoded strings wstring_convert<codecvt_utf8_utf16<wchar_t> > converter; // Convert the LPCWSTR to a wstring and then to an // std::string return converter.to_bytes(wstring(lpcwszStr)); } int main() { // Example LPCWSTR LPCWSTR wideStr = L"w3wiki"; // Convert LPCWSTR to std::string string str = ConvertLPCWSTRToString(wideStr); // Print the converted string cout << str << endl; return 0; } |
Output
w3wiki
Explanation
- The LPCWSTR input is directly converted to a std::wstring object.
- The std::wstring object is then passed to the to_bytes member function of the std::wstring_convert object, which converts it to a std::string using the specified encoding.
Convert LPCWSTR to std::string in C++
In C++, strings can be represented using different character encodings. LPCWSTR stands for Long Pointer to Constant Wide STRing. The LPCWSTR type represents a wide string using the UTF-16 encoding, while the std::string type typically represents a narrow string using the UTF-8 encoding. Converting between these two types requires careful handling of character encodings to ensure data integrity.
In this article, we’ll explore three different approaches to convert an LPCWSTR to a std::string in C++.