Function ImFormatStringToTempBufferV

src/imgui/imgui.cpp:2244–2273

FIXME: Should rework API toward allowing multiple in-flight temp buffers (easier and safer for caller) by making the caller acquire a temp buffer token, with either explicit or destructor release, e.g. ImGuiTempBufferToken token; ImFormatStringToTempBuffer(token, ...);

//  ImGuiTempBufferToken token;
//  ImFormatStringToTempBuffer(token, ...);
void ImFormatStringToTempBufferV(const char** out_buf, const char** out_buf_end, const char* fmt, va_list args)
{
    ImGuiContext& g = *GImGui;
    if (fmt[0] == '%' && fmt[1] == 's' && fmt[2] == 0)
    {
        const char* buf = va_arg(args, const char*); // Skip formatting when using "%s"
        if (buf == NULL)
            buf = "(null)";
        *out_buf = buf;
        if (out_buf_end) { *out_buf_end = buf + ImStrlen(buf); }
    }
    else if (fmt[0] == '%' && fmt[1] == '.' && fmt[2] == '*' && fmt[3] == 's' && fmt[4] == 0)
    {
        int buf_len = va_arg(args, int); // Skip formatting when using "%.*s"
        const char* buf = va_arg(args, const char*);
        if (buf == NULL)
        {
            buf = "(null)";
            buf_len = ImMin(buf_len, 6);
        }
        *out_buf = buf;
        *out_buf_end = buf + buf_len; // Disallow not passing 'out_buf_end' here. User is expected to use it.
    }
    else
    {
        int buf_len = ImFormatStringV(g.TempBuffer.Data, g.TempBuffer.Size, fmt, args);
        *out_buf = g.TempBuffer.Data;
        if (out_buf_end) { *out_buf_end = g.TempBuffer.Data + buf_len; }
    }
}

#ifndef IMGUI_ENABLE_SSE4_2_CRC
// CRC32 needs a 1KB lookup table (not cache friendly)