的libpng +的boost :: GIL：png_infopp_NULL沒有找到

Question

我總是試圖編譯我的文件用的boost :: GIL PNG IO支持時，此錯誤：

（我運行Mac OS X Leopard和升壓1.42， LibPNG 1.4）

/usr/local/include/boost/gil/extension/io/png_io_private.hpp: In member function 'void boost::gil::detail::png_reader::init()': 
/usr/local/include/boost/gil/extension/io/png_io_private.hpp:155: error: 'png_infopp_NULL' was not declared in this scope 
/usr/local/include/boost/gil/extension/io/png_io_private.hpp:160: error: 'png_infopp_NULL' was not declared in this scope 
/usr/local/include/boost/gil/extension/io/png_io_private.hpp: In destructor 'boost::gil::detail::png_reader::~png_reader()': 
/usr/local/include/boost/gil/extension/io/png_io_private.hpp:174: error: 'png_infopp_NULL' was not declared in this scope 
/usr/local/include/boost/gil/extension/io/png_io_private.hpp: In member function 'void boost::gil::detail::png_reader::apply(const View&)': 
/usr/local/include/boost/gil/extension/io/png_io_private.hpp:186: error: 'int_p_NULL' was not declared in this scope 
/usr/local/include/boost/gil/extension/io/png_io_private.hpp: In member function 'void boost::gil::detail::png_reader_color_convert<CC>::apply(const View&)': 
/usr/local/include/boost/gil/extension/io/png_io_private.hpp:228: error: 'int_p_NULL' was not declared in this scope 
/usr/local/include/boost/gil/extension/io/png_io_private.hpp: In member function 'void boost::gil::detail::png_writer::init()': 
/usr/local/include/boost/gil/extension/io/png_io_private.hpp:317: error: 'png_infopp_NULL' was not declared in this scope 

Answer 1

最初我使用libpng 1.4。我切換到版本1.2，所有的問題都消失了。

Answer 2

libpng 1.4丟棄了png_infopp_NULL和int_p_NULL的定義。因此，在包含GIL頭文件之前，在您的代碼中添加

#define png_infopp_NULL (png_infopp)NULL 
#define int_p_NULL (int*)NULL 

。