23e59c8633
Current g++ 7 snapshot fails to compile pybind under -std=c++17 with:
```
$ make
[ 3%] Building CXX object tests/CMakeFiles/pybind11_tests.dir/pybind11_tests.cpp.o
In file included from /home/jagerman/src/pybind11/tests/pybind11_tests.h:2:0,
from /home/jagerman/src/pybind11/tests/pybind11_tests.cpp:10:
/home/jagerman/src/pybind11/include/pybind11/pybind11.h: In instantiation of 'pybind11::cpp_function::initialize(Func&&, Return (*)(Args ...), const Extra& ...)::<lambda(pybind11::detail::function_record*, pybind11::handle, pybind11::handle, pybind11::handle)> [with Func = pybind11::cpp_function::cpp_function(Return (Class::*)(Arg ...), const Extra& ...) [with Return = int; Class = ConstructorStats; Arg = {}; Extra = {pybind11::name, pybind11::is_method, pybind11::sibling}]::<lambda(ConstructorStats*)>; Return = int; Args = {ConstructorStats*}; Extra = {pybind11::name, pybind11::is_method, pybind11::sibling}]':
/home/jagerman/src/pybind11/include/pybind11/pybind11.h:120:22: required from 'struct pybind11::cpp_function::initialize(Func&&, Return (*)(Args ...), const Extra& ...) [with Func = pybind11::cpp_function::cpp_function(Return (Class::*)(Arg ...), const Extra& ...) [with Return = int; Class = ConstructorStats; Arg = {}; Extra = {pybind11::name, pybind11::is_method, pybind11::sibling}]::<lambda(ConstructorStats*)>; Return = int; Args = {ConstructorStats*}; Extra = {pybind11::name, pybind11::is_method, pybind11::sibling}]::<lambda(struct pybind11::detail::function_record*, class pybind11::handle, class pybind11::handle, class pybind11::handle)>'
/home/jagerman/src/pybind11/include/pybind11/pybind11.h:120:19: required from 'void pybind11::cpp_function::initialize(Func&&, Return (*)(Args ...), const Extra& ...) [with Func = pybind11::cpp_function::cpp_function(Return (Class::*)(Arg ...), const Extra& ...) [with Return = int; Class = ConstructorStats; Arg = {}; Extra = {pybind11::name, pybind11::is_method, pybind11::sibling}]::<lambda(ConstructorStats*)>; Return = int; Args = {ConstructorStats*}; Extra = {pybind11::name, pybind11::is_method, pybind11::sibling}]'
/home/jagerman/src/pybind11/include/pybind11/pybind11.h:62:9: required from 'pybind11::cpp_function::cpp_function(Return (Class::*)(Arg ...), const Extra& ...) [with Return = int; Class = ConstructorStats; Arg = {}; Extra = {pybind11::name, pybind11::is_method, pybind11::sibling}]'
/home/jagerman/src/pybind11/include/pybind11/pybind11.h:984:22: required from 'pybind11::class_<type_, options>& pybind11::class_<type_, options>::def(const char*, Func&&, const Extra& ...) [with Func = int (ConstructorStats::*)(); Extra = {}; type_ = ConstructorStats; options = {}]'
/home/jagerman/src/pybind11/tests/pybind11_tests.cpp:24:47: required from here
/home/jagerman/src/pybind11/include/pybind11/pybind11.h:147:9: sorry, unimplemented: unexpected AST of kind cleanup_stmt
};
^
/home/jagerman/src/pybind11/include/pybind11/pybind11.h:147:9: internal compiler error: in potential_constant_expression_1, at cp/constexpr.c:5593
0x84c52a potential_constant_expression_1
../../src/gcc/cp/constexpr.c:5593
0x84c3c0 potential_constant_expression_1
../../src/gcc/cp/constexpr.c:5154
0x645511 finish_function(int)
../../src/gcc/cp/decl.c:15527
0x66e80b instantiate_decl(tree_node*, int, bool)
../../src/gcc/cp/pt.c:22558
0x6b61e2 instantiate_class_template_1
../../src/gcc/cp/pt.c:10444
0x6b61e2 instantiate_class_template(tree_node*)
../../src/gcc/cp/pt.c:10514
0x75a676 complete_type(tree_node*)
../../src/gcc/cp/typeck.c:133
0x67d5a4 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool, bool)
../../src/gcc/cp/pt.c:17516
0x67ca19 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool, bool)
../../src/gcc/cp/pt.c:16655
0x672cce tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
../../src/gcc/cp/pt.c:16140
0x6713dc tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
../../src/gcc/cp/pt.c:15408
0x671915 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
../../src/gcc/cp/pt.c:15394
0x671fc0 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
../../src/gcc/cp/pt.c:15618
0x66e97f tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
../../src/gcc/cp/pt.c:15379
0x66e97f instantiate_decl(tree_node*, int, bool)
../../src/gcc/cp/pt.c:22536
0x6ba0cb instantiate_pending_templates(int)
../../src/gcc/cp/pt.c:22653
0x6fd7f8 c_parse_final_cleanups()
../../src/gcc/cp/decl2.c:4512
```
which looks a lot like https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77545.
The error seems to be that it gets confused about the `std::tuple<...>
value` in argument_loader: it is apparently not being initialized
properly. Adding a default constructor with an explicit
default-initialization of `value` works around the problem.
|
||
|---|---|---|
| docs | ||
| include/pybind11 | ||
| pybind11 | ||
| tests | ||
| tools | ||
| .appveyor.yml | ||
| .gitignore | ||
| .gitmodules | ||
| .travis.yml | ||
| CMakeLists.txt | ||
| CONTRIBUTING.md | ||
| LICENSE | ||
| MANIFEST.in | ||
| README.md | ||
| setup.cfg | ||
| setup.py | ||
pybind11 — Seamless operability between C++11 and Python
pybind11 is a lightweight header-only library that exposes C++ types in Python and vice versa, mainly to create Python bindings of existing C++ code. Its goals and syntax are similar to the excellent Boost.Python library by David Abrahams: to minimize boilerplate code in traditional extension modules by inferring type information using compile-time introspection.
The main issue with Boost.Python—and the reason for creating such a similar project—is Boost. Boost is an enormously large and complex suite of utility libraries that works with almost every C++ compiler in existence. This compatibility has its cost: arcane template tricks and workarounds are necessary to support the oldest and buggiest of compiler specimens. Now that C++11-compatible compilers are widely available, this heavy machinery has become an excessively large and unnecessary dependency.
Think of this library as a tiny self-contained version of Boost.Python with everything stripped away that isn't relevant for binding generation. Without comments, the core header files only require ~2.5K lines of code and depend on Python (2.7 or 3.x) and the C++ standard library. This compact implementation was possible thanks to some of the new C++11 language features (specifically: tuples, lambda functions and variadic templates). Since its creation, this library has grown beyond Boost.Python in many ways, leading to dramatically simpler binding code in many common situations.
Tutorial and reference documentation is provided at http://pybind11.readthedocs.org/en/master. A PDF version of the manual is available here.
Core features
pybind11 can map the following core C++ features to Python
- Functions accepting and returning custom data structures per value, reference, or pointer
- Instance methods and static methods
- Overloaded functions
- Instance attributes and static attributes
- Arbitrary exception types
- Enumerations
- Callbacks
- Iterators and ranges
- Custom operators
- Single and multiple inheritance
- STL data structures
- Iterators and ranges
- Smart pointers with reference counting like
std::shared_ptr - Internal references with correct reference counting
- C++ classes with virtual (and pure virtual) methods can be extended in Python
Goodies
In addition to the core functionality, pybind11 provides some extra goodies:
-
pybind11 uses C++11 move constructors and move assignment operators whenever possible to efficiently transfer custom data types.
-
It is possible to bind C++11 lambda functions with captured variables. The lambda capture data is stored inside the resulting Python function object.
-
It's easy to expose the internal storage of custom data types through Pythons' buffer protocols. This is handy e.g. for fast conversion between C++ matrix classes like Eigen and NumPy without expensive copy operations.
-
pybind11 can automatically vectorize functions so that they are transparently applied to all entries of one or more NumPy array arguments.
-
Python's slice-based access and assignment operations can be supported with just a few lines of code.
-
Everything is contained in just a few header files; there is no need to link against any additional libraries.
-
Binaries are generally smaller by a factor of at least 2 compared to equivalent bindings generated by Boost.Python. A recent pybind11 conversion of PyRosetta, an enormous Boost.Python binding project, reported a binary size reduction of 5.4x and compile time reduction by 5.8x.
-
When supported by the compiler, two new C++14 features (relaxed constexpr and return value deduction) are used to precompute function signatures at compile time, leading to smaller binaries.
-
With little extra effort, C++ types can be pickled and unpickled similar to regular Python objects.
Supported compilers
- Clang/LLVM (any non-ancient version with C++11 support)
- GCC (any non-ancient version with C++11 support)
- Microsoft Visual Studio 2015 or newer
- Intel C++ compiler 16 or newer (15 with a workaround)
- Cygwin/GCC (tested on 2.5.1)
About
This project was created by Wenzel Jakob. Significant features and/or improvements to the code were contributed by Jonas Adler, Sylvain Corlay, Trent Houliston, Axel Huebl, @hulucc, Sergey Lyskov Johan Mabille, Tomasz Miąsko, Dean Moldovan, Ben Pritchard, Jason Rhinelander, Boris Schäling, Pim Schellart, and Ivan Smirnov.
License
pybind11 is provided under a BSD-style license that can be found in the
LICENSE file. By using, distributing, or contributing to this project,
you agree to the terms and conditions of this license.