tree 9a09da4503b77e1958f5ab2b9978f5dbf1768181
parent 55d9559c6ec13907c1c43e6d1385d851d48ca22a
author Brad Bishop <bradleyb@fuzziesquirrel.com> 1629412506 -0400
committer Deepak Kodihalli <deepak.kodihalli.83@gmail.com> 1629781344 +0000

treewide: remove 'using namespace' from headers

Using namespace at global scope in a header file violates the cpp core
guidelines.  Quoting the guidelines:

  "Doing so takes away an #includer’s ability to effectively
disambiguate and to use alternatives. It also makes #included headers
order-dependent as they might have different meaning when included in
different orders."

For further reading:
https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#Rs-using-directive

The guidelines don't call out using using namespace from namespace
scope, but it is only marginally less problematic and still unexpected,
so this patch removes those as well.

The process used to do the update is roughly:

1 - git grep 'using namespace' **.hpp
2 - For each instance, remove the offending 'using namespace' line
3 - build
4 - add 'using namespace' to cpp files or fully resolve types in hpp
  files until the project builds again.

Further cleanup is possible - for example cpp files could be scrubbed
for unnecessary namespace qualification - this was not done here to make
review as simple as possible.

Change-Id: I4931f5e78a1b5b74b4a4774c035a549f4d59b91a
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>