在类定义中写下 static const int size = 100;对不对呀？

whyglinux

先贴上一段关于这个问题的 C++ 标准的原文，等有时间了再发表自己对此的看法。

If a 'static' data member is of 'const' integral or 'const' enumeral type,
  its declaration in the class definition can specify a 'constant-initializer'
  which shall be an integral constant expression (5.19).  In that case, the
  member can appear in integral constant expressions.  The member shall still
  be defined in a namespace scope if it is used in the program and the
  namespace scope definition shall not contain an 'initializer'.