pcc/ninja — comment on commit ff9cc51b9e52f7ae8c3de0ea1cc3df2123e78553
File: src/build.h line 139
By martine:

Ah, in all Google code (including Chrome) there's a macro to do just that. I should probably copy it over eventually.
http://codesearch.google.com/codesearch#search/&exact_package=chromium&q=disallow_implicit&type=cs