Conflicting types的报错

mac上xcode其实给出的错误信息比较多，而且非常有用，大概报错如下：

Conflicting types for 'glDepthRange':
In file included from xxx.cpp
In file included from xxx.cpp
In file included from xxx.cpp
Expanded from macro 'glDepthRangef'
revious declaration is here

我是因为OpenGL的头文件必须在glew.h前声明，所以对头文件的引入顺序有要求

一定要仔细的排查In file included from，排查这个代码里面的include，确保include嵌套也不会出问题，确保里面的顺序。

vtable for xxx

‘

: "vtable for TouchLayer", referenced from:
: A missing vtable usually means the first non-inline virtual member function has no definition.

大概意思就是有虚函数没有实现，但是我仔细检查了代码，不存在这个问题，因为我使用的是cmake，所以排查后发现，cpp文件没有加入到工程里面，加入到里面就正常通过编译了。