EzoeRyou/cpp-book — pull request #72 by tzik (2013-11-01 18:51:05+00:00)
Title: fix pure virtual function

純粋仮想関数にout-of-lineな定義を与えるのは別に禁止されていないのでは。

> A pure virtual function need be deﬁned only if called with, or as if with (12.4), the qualiﬁed-id syntax (5.1).
ref: 10.4: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3337.pdf