VC 链接时new和delete运算符已经在 LIBCMTD.lib 中定义解决方法

error LNK2005: "void * __cdecl operator new(unsigned int)" (??2@YAPAXI@Z) 已经在 LIBCMTD.lib(new.obj) 中定义

error LNK2005: "void __cdecl operator delete(void *)" (??3@YAXPAX@Z) 已经在 LIBCMTD.lib(dbgdel.obj) 中定义

error LNK2005: "void * __cdecl operator new[](unsigned int)" (??_U@YAPAXI@Z) 已经在 LIBCMTD.lib(new2.obj) 中定义
error LNK2005: "void __cdecl operator delete[](void *)" (??_V@YAXPAX@Z) 已经在 LIBCMTD.lib(delete2.obj) 中定义
上网搜了下，是CRT库与MFC库的冲突，解决方法是：让程序先链接Nafxcwd.lib,然后再链接Libcmtd.lib

you've got to change the order inwhich the libraries are linked. This is a bit tricky, since the library are linked automatically, without you explicitly specifying them.

So, first step, tell the linker to ignore the implicit libraries: Project/Setting/Linker, Input Tab, and put "Nafxcwd.lib Libcmtd.lib" in the "Libraries to Ignore" box.

Next, on the same page, in the Object/library Modules box, put the same to libraries. (in you still get the same error, try reversing them on this line)
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中文

项目--属性 ---连接器---输入  

                              附加依赖项    空格Nafxcwd.lib Libcmtd.lib

                              忽略指定库    空格Nafxcwd.lib Libcmtd.lib

清除项目。重新编译。搞定

文章来源：http://www.cnblogs.com/xianqingzh/archive/2009/10/29/1591868.html