解决方法
如果你使用MSVC：
你不能通过设置一个标志来逃避这种类型的错误：它意味着一些单位(.cpp)不具有声明的标识符的定义.它肯定是由某个地方缺少包含或缺少对象定义(通常是静态对象)引起的.
在开发过程中,您可以遵循这些准则(从those articles开始),以确保所有cpp包含他们需要的所有标题,但不再包括：
- Every cpp file includes its own header file first. This is the most
important guideline; everything else
follows from here. The only exception
to this rule are precompiled header
includes in Visual Studio; those
always have to be the first include in
the file. More about precompiled
headers in part two of this article.- A header file must include all the header files necessary to parse it.
This goes hand in hand with the first
guideline. I kNow some people try to
never include header files within
header files claiming efficiency or
something along those lines. However,
if a file must be included before a
header file can be parsed,it has to
be included somewhere. The advantage
of including it directly in the header
file is that we can always decide to
pull in a header file we’re interested
in and we’re guaranteed that it’ll
work as is. We don’t have to play the
“guess what other headers you need”
game.- A header file should have the bare minimum number of header files
necessary to parse it. The prevIoUs
rule said you should have all the
includes you need in a header file.
This rule says you shouldn’t have any
more than you have to. Clearly,start
by removing (or not adding in the
first place) useless include
statements. Then,use as many forward
declarations as you can instead of
includes. If all you have are
references or pointers to a class,you
don’t need to include that class’
header file; a forward reference will
do nicely and much more efficiently.
但是正如评论者的建议,似乎你正在使用g …
