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Subject: [geometry] Support of C++11 initializer list
From: Adam Wulkiewicz (adam.wulkiewicz_at_[hidden])
Date: 2015-01-23 21:36:52


Some time ago I added an experimental support for C++ initializer lists in
geometries to make possible the creation of geometries using uniform
initialization, e.g.:

linestring ls = {{0, 0},{1, 1},{2, 2}};
polygon poly = {{{0, 0},{0, 5},{5, 5},{5, 0},{0, 0}},{{1, 1},{4, 1},{4,
4},{1, 4},{1, 1}}};

The goal was to support C++11 initializer lists and Boost.Assign in the
same time even if Boost.Assign currently doesn't work on all compilers with
STL containers. FYI, there is a PR with proposed fix but nobody is willing
to merge it.

Anyway, to work around it and avoid ambiguity while using Boost.Assign to
assign new data to the geometry I implemented only the constructor taking
std::initializer_list. This way the compiler prefers the conversion from
Boost.Assign generic_list directly into the Geometry because conversion
first to std::initializer_list would require 1 more conversion.

It seems that everything is ok on all compilers except the msvc14 CTP, I
hope they'll fix it in the final release. See, the
test geometries.

So if you'd like to try it out you have to checkout the develop branch and
know if it works for you.

The final question is, should we enable it by default in Boost 1.58?


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