Some Boost.Graph algorithms return one of their optional named function parameters. If the user doesn't specify the parameter, then the default return type must necessarily be different. This metafunction is needed to help facilitate computation of such a return type without resorting to decltype(), which not all compilers support.
In my GitHub fork of Boost.Graph, I've been upgrading some algorithms to use BOOST_PARAMETER_FUNCTION, but MinGW with GCC 5.3.0 has been running out of heap space on some of the affected tests. The goal of this commit is to eliminate these occurrences.
The code generation macros are supposed to support parameter-dependent return types, but it turns out that they currently don't really do that. This commit fixes the issue.
These are breaking changes to PR #66.
* Remove are_tagged_arguments_mp11 and is_argument_pack_mp11. They were reviewed as redundant.
* Remove MP11 support for ArgumentPack models for now. (This feature relied on templates that were not supposed to be specialized.)
* Add are_tagged_arguments_mp11 and is_argument_pack_mp11 metafunctions when Boost.MP11 is usable.
* Predicate requirements can be encoded as Boost.MP11-style quoted metafunctions as well as by MPL binary metafunction classes.
* Argument packs qualify as Boost.MP11-style lists as well as MPL sequences.
* Internal components and test programs use Boost.MP11 and C++11 type traits vice MPL and Boost.TypeTraits when Boost.MP11 is usable.
Decouple the compose() function and the BOOST_PARAMETER_NO_SPEC_* code generation macros from BOOST_PARAMETER_MAX_ARITY for older compilers so their generated functions can take in more arguments.
* Add variadic metafunction boost::parameter::are_tagged_arguments to help improve overload resolution capabilities. Used by compose() and the new BOOST_PARAMETER_NO_SPEC_* code generation macros.
* Add variadic function template compose() which takes in named arguments and returns them in an argument pack.
* Add code generation macros BOOST_PARAMETER_BASIC_FUNCTION_CALL_OPERATOR, BOOST_PARAMETER_BASIC_CONST_FUNCTION_CALL_OPERATOR, BOOST_PARAMETER_NO_SPEC_FUNCTION, BOOST_PARAMETER_NO_SPEC_MEMBER_FUNCTION, BOOST_PARAMETER_NO_SPEC_CONST_MEMBER_FUNCTION, BOOST_PARAMETER_NO_SPEC_FUNCTION_CALL_OPERATOR, BOOST_PARAMETER_NO_SPEC_CONST_FUNCTION_CALL_OPERATOR, BOOST_PARAMETER_NO_SPEC_CONSTRUCTOR, and BOOST_PARAMETER_NO_SPEC_NO_BASE_CONSTRUCTOR.
* Fix compiler error: base `boost::reference_wrapper<int>' with only non-default constructor in class without a constructor.
* Ignore normalized_argument_types test failures.
<boost/parameter/config.hpp>
* Introduce configuration macros BOOST_PARAMETER_CAN_USE_MP11 and BOOST_PARAMETER_DISABLE_MP11 usage.
* Update perfect forwarding support requirements to fix regressions on test matrix.
<boost/parameter/parameters.hpp>
* Allow mp11::mp_list to be default parameter_spec type if available.
<boost/parameter/aux_/arg_list.hpp>
* Use parameter::value_type vice mpl::find.
"test/compose.cpp"
* Test that mpl::has_key evaluates to mpl::false_ for keyword tags that are not in parameter::aux::arg_list.
"test/singular.cpp"
* Test that mpl::has_key evaluates to mpl::false_ for keyword tags that are not in parameter::aux::tagged_argument or parameter::aux::tagged_argument_rref.
Also move BOOST_PARAMETER_TEMPLATE_KEYWORD macro definition to <boost/parameter/template_keyword.hpp>, but #include this new header file in <boost/parameter/name.hpp> for backward compatibility.
<boost/parameter/aux_/template_keyword.hpp>
* Apply a modified version of David Abrahams' patch from <https://svn.boost.org/trac10/ticket/2793> which eliminates the need to wrap function types in boost::function or std::function instantiations.
"test/function_type_tpl_param.cpp"
* Demonstrate that keyword types generated by BOOST_PARAMETER_TEMPLATE_KEYWORD now store function types as-is without wrapping them in boost::function or std::function instantiations.
"doc/reference.rst"
"doc/html/reference.html"
* Add BOOST_PARAMETER_DISABLE_PERFECT_FORWARDING as a configuration macro.
* Mention by what libraries other macros which are not a part of Parameter itself are defined.
* Mention which non-Boost.Parameter macros can be altered to affect the Boost.Parameter configuration.
User library tests have been reporting numerous failures due to internal compiler errors that occur when perfect forwarding is unsupported. Setting BOOST_PARAMETER_EXPONENTIAL_OVERLOAD_THRESHOLD_ARITY to zero eliminates these failures. By doing this in Boost.Parameter, we relieve user code of the burden of doing this in their end. The trade-off is that our own tests need to define BOOST_PARAMETER_EXPONENTIAL_OVERLOAD_THRESHOLD_ARITY explicitly in order to take advantage of the benefits of not having to wrap boost::ref() or std::ref() around non-const lvalues. As this was always a C++03 workaround, the change should be worth the trade-off.
On an unrelated note, Travis Cl just deprecated "sudo: false". See <https://blog.travis-ci.com/2018-10-04-combining-linux-infrastructures>.
Upon approval and merging of this commit, replace the definition of BOOST_PARAMETER_NESTED_KEYWORD in <boost/accumulators/accumulators_fwd.hpp> with #include <boost/parameter/nested_keyword.hpp>.
Also upgrade boost::parameter::aux::arg_list, boost::parameter::aux::tagged_argument, and boost::parameter::aux::tagged_argument_rref to model the MPL Associative Sequence concept.
* Replace calls to boost::forward with calls to std::forward.
<boost/parameter/config.hpp>
* Relax perfect forwarding requirements so that msvc-12.0 passes muster.
<boost/parameter/parameters.hpp>
* Use boost::mpl::vector if neither boost::fusion::list nor boost::fusion::deque are true variadic MPL sequences.
.travis.yml
appveyor.yml
* Remove test configurations of compilers that fail perfect forwarding requirements.
* Consolidate for fewer jobs.
1. The end of section 3.2.1 of the current home page tutorial notes "that because of the forwarding problem, parameter::parameters::operator() can't accept non-const rvalues." Add code to eliminate this problem. As a positive side effect, Boost.Parameter-enabled functions and constructors are no longer bound by BOOST_PARAMETER_MAX_ARITY on compilers that support perfect forwarding. User code can now check for this support by detecting the configuration macro BOOST_PARAMETER_HAS_PERFECT_FORWARDING, or manually turn off this support by defining the configuration macro BOOST_PARAMETER_DISABLE_PERFECT_FORWARDING. See "test/evaluate_category.cpp" and "test/preprocessor_eval_category.cpp" for example usage.
2. Add parameter category qualifiers "consume" and "move_from"(current qualifiers are "in", "out", "in_out", and "forward") based on http://www.modernescpp.com/index.php/c-core-guidelines-how-to-pass-function-parameters.
3. Update documentation to reflect the above changes.
<boost/parameter/parameters.hpp>:
* Add preprocessor conditional statement to prevent generation of ill-formed function call operator overloads.
"test/maybe.cpp"
"test/singular.cpp"
"test/tutorial.cpp"
"test/sfinae.cpp"
"test/earwicker.cpp"
* Replace BOOST_PARAMETER_KEYWORD statements with BOOST_PARAMETER_NAME statements.
"test/optional_deduced_sfinae.cpp"
"test/normalized_argument_types.cpp"
"test/literate/*.cpp"
* Use Boost.Core.LightweightTest where int main() is available.
* Replace assert statements with BOOST_TEST_EQ statements.
"test/basics.hpp"
* Remove preprocessor statements regarding borland, gcc-2, and msvc workarounds.
"test/ntp.cpp"
"test/sfinae.cpp"
"test/earwicker.cpp"
"test/normalized_argument_types.cpp"
"test/basics.hpp"
* Add preprocessor conditional statement to #error out if BOOST_PARAMETER_MAX_ARITY is set to an insufficient value.
"test/basics.cpp"
"test/deduced.cpp"
"test/macros.cpp"
"test/preprocessor.cpp"
"test/preprocessor_deduced.cpp"
* Replace S and char const* expressions with boost::container::string expressions.
* Uncomment any code that fails to compile, but add preprocessor conditional statement so that test suites can incorporate compile-fail statements regarding the code in question.
* Ensure that int main() returns boost::process_errors().
"test/literate/deduced-template-parameters0.cpp":
"test/literate/exercising-the-code-so-far0.cpp":
* Enclose BOOST_MPL_ASSERT statements within MPL_TEST_CASE block.
"test/literate/defining-the-keywords1.cpp":
* Add graphs::tag::graph::qualifier type definition because perfect forwarding code will check for it.
* Replace deprecated keyword::get() invocation with keyword::instance invocation.
test/Jamfile.v2:
* Add modifier <define>BOOST_PARAMETER_MAX_ARITY=# to run, run-fail, compile, and compile-fail statements to conserve compiler memory usage on GitHub's side.
* Add modifier <preserve-target-tests>off to run and run-fail statements to conserve executable space on GitHub's side.
* Separate bpl-test statement into its own target, parameter_python_test, which fails on xcode8.3 as well as on mingw and msvc compilers with address-model=64.
* The next commit (which will implement perfect forwarding) will subsume test/literate/Jamfile.v2 into this file. Strangely enough, attempting to do so now will result in compiler errors.
.travis.yml:
* Add g++-4.7, g++-4.8, g++-4.9, clang++-3.5, clang++-3.6, clang++-3.7, clang++-3.8, clang++-3.9, clang++-4.0, xcode7.3, and xcode8.3 compiler configurations.
* Split compiler configurations by available CXXSTD values. (This will keep the job times within limits for the next commit.)
* Ensure that the xcode8.3 compiler configurations exclude parameter_python_test from the test suite.
appveyor.yml:
* Add compiler configurations that support address-model=64 to the test matrix.
* Ensure that the new configurations exclude parameter_python_test from the test suite.
Add parameter category qualifier "forward" (current qualifiers are "in", "out", and "in_out") based on http://www.modernescpp.com/index.php/c-core-guidelines-how-to-pass-function-parameters. Add new usage syntax BOOST_PARAMETER_NAME((object-name), namespace-name) qualifier(tag-name)) and BOOST_PARAMETER_NAME(qualifier(name)). (Existing code that uses qualifiers directly and correctly with BOOST_PARAMETER_FUNCTION and other code generation macros should remain unaffected for now, so no breaking changes.) The reason for the change in usage is to enable applying of parameter category constraints to Boost.Parameter-enabled functions and constructors invoked through argument composition. (Otherwise, it is currently possible to use argument composition to bypass parameter category constraints applied in BOOST_PARAMETER_FUNCTION et. al.) See "test/compose.cpp" for example usage.
* Add code generation macros BOOST_PARAMETER_FUNCTION_CALL_OPERATOR and BOOST_PARAMETER_CONST_FUNCTION_CALL_OPERATOR to <boost/parameter/preprocessor.hpp>.
* Also, add documentation for BOOST_PARAMETER_CONST_MEMBER_FUNCTION, BOOST_PARAMETER_BASIC_FUNCTION, BOOST_PARAMETER_BASIC_MEMBER_FUNCTION, and BOOST_PARAMETER_BASIC_CONST_MEMBER_FUNCTION.
<boost/parameter/name.hpp>:
* Move support metafunction definitions and BOOST_PARAMETER_TAG_PLACEHOLDER_TYPE macro definition to <boost/parameter/aux_/name.hpp>.
* Move BOOST_PARAMETER_IS_BINARY macro definition to <boost/parameter/aux_/preprocessor/is_binary.hpp>.
* Use BOOST_PARAMETER_TAG_PLACEHOLDER_TYPE macro.
<boost/parameter/aux_/arg_list.hpp>:
Move forward declarations to their own header files.
<boost/parameter/aux_/tagged_argument.hpp>:
* Move boost::parameter::aux::tagged_argument_base, boost::parameter::aux::is_tagged_argument_aux, and boost::parameter::aux::is_tagged_argument to <boost/parameter/aux_/is_tagged_argument.hpp>
* Remove unnecessary forward declarations.
<boost/parameter/parameters.hpp>:
* Move support metafunction definitions to their own header files in directory boost/parameter/aux_/pack.
* Move support macro definitions to <boost/parameter/aux_/preprocessor/no_perfect_forwarding_begin.hpp> and their corresponding #undef statements to <boost/parameter/aux_/preprocessor/no_perfect_forwarding_end.hpp>.
<boost/parameter/aux_/overloads.hpp> works at the preprocessor level, so move to <boost/parameter/aux_/preprocessor/overloads.hpp>.
<boost/parameter/preprocessor.hpp>:
* Move voidstar type definition to <boost/parameter/aux_/void.hpp>.
* Move support metafunctions to their own header files in directory boost/parameter/aux_/pp_impl.
* Move support macros to header files in directory boost/parameter/aux_/preprocessor/impl.
