Tip of the Week #153: Don’t use using-directives
▻https://abseil.io/tips/153
Originally posted as TotW #153 on July 17, 2018
by Roman Perepelitsa (roman.perepelitsa@gmail.com) and Ashley Hedberg (ahedberg@google.com)
I view using-directives as time-bombs, both for the parties that deal in them and the language system. – Ashley Hedberg with apologies to Warren Buffett
tl;dr
Using-directives (using namespace foo) are dangerous enough to be banned by the Google style guide. Don’t use them in code that will ever need to be upgraded.
These are not to be confused with using-declarations (using ::foo::SomeName), which are permitted in *.cc files.
Using-directives at Function Scope
What do you think this code does?
namespace totw namespace example namespace
TEST(MyTest, UsesUsingDirectives) using namespace ::testing; Sequence seq; // ::testing::Sequence (...)