Brace initialization for simple POD classes #1015
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Nice. Making simple structs simpler.
This is a minor corner case, but since initializer_list takes priority over regular constructors when brace initialization is used (the std::vector<int> issue), somebody somewhere may be affected when upgrading. Might be worth mentioning in the docs.
tests/test_class.cpp
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| @@ -229,6 +229,16 @@ TEST_SUBMODULE(class_, m) { | |||
| // This test is actually part of test_local_bindings (test_duplicate_local), but we need a | |||
| // definition in a different compilation unit within the same module: | |||
| bind_local<LocalExternal, 17>(m, "LocalExternal", py::module_local()); | |||
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| struct BraceInitialization { | |||
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Just a quick comment above this line: // test_brace_initializaton
Having the name of the Python test function as a comment above the corresponding C++ code makes it very convenient to navigate from a failed test function to the C++ source.
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done. |
I deliberately keep the fatal: The upstream branch of your current branch does not match
the name of your current branch. To push to the upstream branch
on the remote, use
git push upstream HEAD:master
To push to the branch of the same name on the remote, use
git push upstream upstreamso that I can still push it using the first suggested command, but it's always an extra safety step (even against ordinary pushes, not just forced pushes). |
docs/advanced/classes.rst
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| .def(py::init<int, const std::string &>()); | ||
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| Note that brace initialization preferentially invokes constructor overloads | ||
| taking a ``std::initializer_list``. |
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Perhaps add:
In the rare event that this causes an issue, you can work around it by using py::init(...) with a lambda function that constructs the new object as desired.
Since that makes it more than just a single sentence, it's probably useful to put it in a note section.
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One small suggested addition to the docs, but otherwise this LGTM. |
docs/advanced/classes.rst
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| .. code-block:: cpp | ||
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| struct POD { |
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Not a POD (std::string is not trivially copyable). Aggregate should be the term for this kind of structure and brace initialization.
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Rebased and squashed down into 2 commits. Unrelated: I noticed a number of warnings when compiling the test suite on Clang/OSX -- at least one of them is related to the new factory constructors. |
Which version of clang? I'm not seeing these with appleclang v8.1.0. (In fact, seems to be reporting |
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It's clang trunk compiled from SVN :). |
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merged. |
For simple POD classes storing just a few fields, I often don't bother writing constructors and use the generalized C++11 brace initialization syntax. pybind11 doesn't like that and currently requires one to add constructors to the POD class (the
py::initdetails use the C++03 syntax). This commit switches the pybind11 implementation to use brace initialization as well.^@jagerman
^@dean0x7d
Unrelated: I almost did a force push to the master branch instead of my personal repo but noticed in the last moment. I switched the master branch to protected status now (i.e. force pushes not allowed) to prevent accidents -- it's easily removed temporarily if we ever need to.