Function ImFormatString

examples/ThirdPartyLibs/imgui/imgui.cpp:1121–1133

// B) When buf==NULL vsnprintf() will return the output size.
#ifndef IMGUI_DISABLE_FORMAT_STRING_FUNCTIONS
int ImFormatString(char* buf, size_t buf_size, const char* fmt, ...)
{
	va_list args;
	va_start(args, fmt);
	int w = vsnprintf(buf, buf_size, fmt, args);
	va_end(args);
	if (buf == NULL)
		return w;
	if (w == -1 || w >= (int)buf_size)
		w = (int)buf_size - 1;
	buf[w] = 0;
	return w;
}

int ImFormatStringV(char* buf, size_t buf_size, const char* fmt, va_list args)
{