yohhoy’s gists

yohhoy / mock-string.cpp

Last active July 2, 2021 02:12

Mock class template

	#include <initializer_list>

	namespace mock {
	template <class T>
	struct allocator {};
	template <class T>
	struct char_traits {};

	// C++20 https://timsong-cpp.github.io/cppwp/n4861/basic.string
	template<class charT, class traits = char_traits<charT>,

yohhoy / utf8_util.hpp

Last active September 15, 2020 04:58

UTF-8 util

	bool starts_with_utf8bom(std::string_view s)
	{
	constexpr char utf8_bom[3] = { 0xEF, 0xBB, 0xBF };
	return s.length() >= 3 && std::equal(utf8_bom, utf8_bom + 3, s.begin());
	}

	std::string& erase_utf8bom(std::string& text)
	{
	if (starts_with_utf8bom(text)) {
	text.erase(0, 3);

yohhoy / decltype.cpp

Created August 17, 2020 06:08

	#include <type_traits>

	int main() {
	int x = 42;
	static_assert(std::is_same_v<decltype( x ), int>);
	static_assert(std::is_same_v<decltype((x)), int&>);

	int (y) = 42; // redundant parentheses
	static_assert(std::is_same_v<decltype( y ), int>);
	static_assert(std::is_same_v<decltype((y)), int&>);

yohhoy / spdlog-templ.cpp

Last active July 15, 2021 07:06

template code for spdlog library

	#include <memory>
	#include <vector>
	#define SPDLOG_ACTIVE_LEVEL SPDLOG_LEVEL_DEBUG
	#include "spdlog/spdlog.h"
	#include "spdlog/sinks/stdout_color_sinks.h"
	#include "spdlog/sinks/daily_file_sink.h"
	#include "spdlog/sinks/rotating_file_sink.h"

	int main(int argc, char* argv[])
	{

yohhoy / same_as.cpp

Last active October 17, 2019 03:27

same_as concept in C++20 Standard Library

	//
	// requires Micosoft VisualC++ 2019 16.3 Preview 2 that implements P0717R1.
	//
	// https://devblogs.microsoft.com/cppblog/c20-concepts-are-here-in-visual-studio-2019-version-16-3/
	// https://wg21.link/p0717r1 Semantic constraint matching for concepts
	#include <type_traits>

	#if 1
	template <class T, class U>
	concept same_as_impl = std::is_same_v<T, U>;

yohhoy / subsume-P0717R1.txt

Last active September 11, 2019 04:53

C++20 Concepts constraints subsumption analysis

	constraint-expressions:
	- C1<T>^c && C2<T>^c
	- C1<T>^d

	# concept version
	template <class T> concept C1<T> = true^a;
	template <class T> concept C2<T> = true^b;

	normal form of P = true^a ∧ true^b
	normal form of Q = true^a

yohhoy / str2tc.c

Created August 19, 2019 05:00

FFmpeg/av_timecode_init_from_string() with "59.94DF" support

	/*
	* https://github.com/intel/ffmpeg_libyami/blob/master/libavutil/timecode.c
	*/
	inline int av_timecode_init_from_string2(AVTimecode* tc, AVRational rate, const char* str)
	{
	#if 0
	return av_timecode_init_from_string(&tc, rate, str, NULL);
	#else
	char c;
	int hh, mm, ss, ff;

yohhoy / TypeSafeBridge.md

Last active June 22, 2019 00:46

// callee.m iOS Native(Objective-C) class
@interface NativeType
- (void)method:(int)arg;
@end

@implementation NativeType
// ...
@end

yohhoy / invokeObjC.c

Created June 14, 2019 18:44

invoke Obj-C from pure-C

	#include <stdlib.h>
	#include <stdio.h>
	#include <string.h>
	#include <ctype.h>
	#include <objc/message.h>


	SEL sel_propSetter(Class clazz, const char* pname)
	{
	char* attr = property_copyAttributeValue(class_getProperty(clazz, pname), "S");

yohhoy / ver.cpp

Created April 18, 2019 15:57

compiler version snippet

	#if defined(__clang__)
	#pragma message "Clang " __VERSION__
	#elif defined(__GNUC__)
	#pragma message "GCC " __VERSION__
	#elif defined(_MSC_VER)
	// https://qiita.com/yumetodo/items/8c112fca0a8e6b47072d
	#define STR(s) #s
	#define DUMP(s) #s "=" STR(s)
	#pragma message ("MSVC " DUMP(_MSC_VER) " " DUMP(_MSC_FULL_VER))
	#endif

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