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Asking Chat GPT about warnings in toolkit.cpp, here is the response for these warnings: Where it discusses a C++17 solution: To address the deprecation warnings you're seeing in your C++ project, you'll need to replace the usage of std::wstring_convert and std::codecvt_utf8 for UTF-16 strings (char16_t). These classes have been deprecated as of C++17. Here's a solution using the newer C++17 standard, which supports more modern and potentially safer alternatives for character encoding conversions. However, note that direct replacements within the standard library are limited, so you might need to either implement a custom solution or use a third-party library like boost::locale. For the purpose of this explanation, I'll suggest a method using only the standard library, although it might be less straightforward than using a library designed for such tasks. Custom Conversion FunctionSince std::codecvt and std::wstring_convert are deprecated and there are no direct replacements in the standard library, you'll need to manually handle the conversion if sticking to the standard library: #include <string>
#include <locale>
#include <codecvt>
#include <vector>
std::string UTF16toUTF8(const std::u16string& input) {
std::wstring_convert<std::codecvt_utf8_utf16<char16_t>, char16_t> convert;
return convert.to_bytes(input);
}
std::u16string UTF8toUTF16(const std::string& input) {
std::wstring_convert<std::codecvt_utf8_utf16<char16_t>, char16_t> convert;
return convert.from_bytes(input);
}Integration in Your Existing CodeYou will replace instances of std::wstring_convert<std::codecvt_utf8<char16_t>, char16_t> with direct calls to these functions. Replacement in toolkit.cppFind and replace the lines where std::wstring_convert and std::codecvt_utf8<char16_t> are used, replacing them with calls to UTF16toUTF8() or UTF8toUTF16() based on the context in which they are used. This often occurs when you're either saving to or reading from files or other data streams that require text encoding conversions. Example UsageWhen you need to convert a std::u16string to std::string for UTF-8 encoding, you would do something like: std::u16string data_u16 = u"Example";
std::string data_utf8 = UTF16toUTF8(data_u16);And for converting back: std::string data_utf8 = "Example";
std::u16string data_u16 = UTF8toUTF16(data_utf8);CautionIf you frequently handle text conversion in your application, consider using a more comprehensive solution like Boost.Locale, which offers extensive support for text processing and character conversions beyond what's provided by the C++ Standard Library. This is especially useful if you need robust error handling and support for a wider range of character encodings. By moving away from deprecated features, your code not only gains in maintainability but also aligns better with future C++ standards, which emphasize more robust and type-safe alternatives. |
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Asking about a C++20 for the toolkit.cpp warnings: In C++20, handling text encoding transformations like UTF-8 to UTF-16 or vice versa can be managed using standard facilities available in for fundamental character conversion operations. However, C++20 does not introduce direct replacements for the full functionality previously provided by std::codecvt and std::wstring_convert. This means that for complete text encoding conversions, additional handling might still be required. Unfortunately, as of my last update, there are no new standard library features in C++20 that directly replace std::wstring_convert and std::codecvt for arbitrary string conversions. The introduction of char8_t in C++20 formalizes support for UTF-8 character sequences, but utilities for conversion between different Unicode encodings (like UTF-8, UTF-16, UTF-32) in the standard library are still limited. Using Third-Party LibrariesGiven the lack of direct support in C++20 for these conversions, many developers turn to third-party libraries for robust support. Libraries like Boost.Locale or ICU (International Components for Unicode) are often used in environments where comprehensive text processing and Unicode support are required. Manual Conversion Example in C++20If sticking to standard C++ and handling basic scenarios without external libraries, you would typically need to manually handle UTF-16 to UTF-8 conversions as shown earlier. For a more "modern" approach utilizing C++20 features, you can still use facilities like std::u8string for UTF-8 and continue handling conversions manually: #include <string>
#include <vector>
std::u8string UTF16toUTF8(const std::u16string& input) {
std::u8string output;
// Placeholder for manual conversion logic
// Real conversion logic here should handle actual UTF-16 to UTF-8 conversion
for (char16_t c : input) {
if (c < 0x80) { // Handle basic ASCII conversion
output.push_back(static_cast<char8_t>(c));
} else {
// Extend this block to handle non-ASCII characters
}
}
return output;
}
std::u16string UTF8toUTF16(const std::u8string& input) {
std::u16string output;
// Placeholder for manual conversion logic
// Real conversion logic here should handle actual UTF-8 to UTF-16 conversion
for (char8_t c : input) {
output.push_back(static_cast<char16_t>(c)); // Naive conversion for ASCII only
}
return output;
}In C++20, handling text encoding transformations like UTF-8 to UTF-16 or vice versa can be managed using standard facilities available in for fundamental character conversion operations. However, C++20 does not introduce direct replacements for the full functionality previously provided by std::codecvt and std::wstring_convert. This means that for complete text encoding conversions, additional handling might still be required. Unfortunately, as of my last update, there are no new standard library features in C++20 that directly replace std::wstring_convert and std::codecvt for arbitrary string conversions. The introduction of char8_t in C++20 formalizes support for UTF-8 character sequences, but utilities for conversion between different Unicode encodings (like UTF-8, UTF-16, UTF-32) in the standard library are still limited. Using Third-Party Libraries Manual Conversion Example in C++20 #include <string>
#include <vector>
std::u8string UTF16toUTF8(const std::u16string& input) {
std::u8string output;
// Placeholder for manual conversion logic
// Real conversion logic here should handle actual UTF-16 to UTF-8 conversion
for (char16_t c : input) {
if (c < 0x80) { // Handle basic ASCII conversion
output.push_back(static_cast<char8_t>(c));
} else {
// Extend this block to handle non-ASCII characters
}
}
return output;
}
std::u16string UTF8toUTF16(const std::u8string& input) {
std::u16string output;
// Placeholder for manual conversion logic
// Real conversion logic here should handle actual UTF-8 to UTF-16 conversion
for (char8_t c : input) {
output.push_back(static_cast<char16_t>(c)); // Naive conversion for ASCII only
}
return output;
}Recommendations1 For simple ASCII data: The above manual methods can be sufficient. In practice, handling complex Unicode data in C++ often still involves leveraging external libraries, especially in applications needing comprehensive internationalization support. |
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@craigsapp this looks like the most appropriate solution for UTF8 to UTF32. I will give a try. |
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See 2e7290c and dir-010 and dir-011 in the test suite. |
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Fixed with 2e7290c |
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In vrv.cpp, there are deprecation warnings:
Asking Chat GPT about these warnings, it seems that C++20 (current compiler version for verovio) has a solution:
To resolve the deprecation warnings related to the usage of std::codecvt_utf8 and std::wstring_convert in your C++ code, you need to update the code to use a modern, non-deprecated approach for handling UTF-8 and UTF-32 conversions. The std::codecvt_utf8 and std::wstring_convert classes have been deprecated as of C++17 due to the complexities and limitations they introduce.
Step 1: Modify UTF-32 to UTF-8 Conversion Function
For converting UTF-32 strings (std::u32string) to UTF-8 (std::string), you can use the char8_t type introduced in C++20. If C++20 is not available, you might need to stick with char and handle UTF-8 encoding explicitly.
Here’s a modified version of the UTF32to8 function using C++11 and later standards without deprecated features:
Step 2: Modify UTF-8 to UTF-32 Conversion Function
Similarly, to convert from UTF-8 to UTF-32:
Integration
Replace calls to the deprecated functions with these new functions in your codebase. These implementations directly manage the UTF-8 encoding without using deprecated features. They should be tested thoroughly, especially for edge cases involving characters at the boundaries of UTF-8 byte sequences.
This update will eliminate the deprecation warnings and future-proof your code against upcoming changes in the C++ standards.
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