doc: fix C++ example compilation on MinGW
The examples under doc/examples/ are compiled with Gnulib, which overrides write if it's not available, as a macro. This conflicts with the usage of std::iostream::write in ex-cxx.cpp. To avoid the build issue, use a custom namespace to hide it, as suggested in: https://www.gnu.org/software/gnulib/manual/html_node/A-C_002b_002b-namespace-for-gnulib.html
Fixes: #1480 (closed)
Checklist
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Commits have Signed-off-by:
with name/author being identical to the commit author -
Code modified for feature -
Test suite updated with functionality tests -
Test suite updated with negative tests -
Documentation updated / NEWS entry present (for non-trivial changes) -
CI timeout is 2h or higher (see Settings/CICD/General pipelines/Timeout)
Reviewer's checklist:
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Any issues marked for closing are addressed -
There is a test suite reasonably covering new functionality or modifications -
Function naming, parameters, return values, types, etc., are consistent and according to CONTRIBUTION.md
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This feature/change has adequate documentation added -
No obvious mistakes in the code