For implementing full move semantics when passing parameters by value.
Based on SWIGTYPE && and std::unique_ptr typemaps which implement move
semantics.
Added for all languages, but untested for: Go, Ocaml, R, Scilab (and
unlikely to be fully functional for same reasons as for std::unique_ptr
support).
Issue #999
The directorin typemaps in the director methods now use std::move on the
input parameter when copying the object from the stack to the heap prior
to the callback into the target language, thereby taking advantage of
move semantics if available.
Enhance SWIGTYPE "out" typemaps to use std::move when copying
objects, thereby making use of move semantics when wrapping a function returning
by value if the returned type supports move semantics.
Wrapping functions that return move only types 'by value' now work out the box
without having to provide custom typemaps.
The implementation removed all casts in the "out" typemaps to allow the compiler to
appropriately choose calling a move constructor, where possible, otherwise a copy
constructor. The implementation alsoand required modifying SwigValueWrapper to
change a cast operator from:
SwigValueWrapper::operator T&() const;
to
#if __cplusplus >=201103L
SwigValueWrapper::operator T&&() const;
#else
SwigValueWrapper::operator T&() const;
#endif
This is not backwards compatible for C++11 and later when using the valuewrapper feature
if a cast is explicitly being made in user supplied "out" typemaps. Suggested change
in custom "out" typemaps for C++11 and later code:
1. Try remove the cast altogether to let the compiler use an appropriate implicit cast.
2. Change the cast, for example, from static_cast<X &> to static_cast<X &&>, using the
__cplusplus macro if all versions of C++ need to be supported.
Issue #999Closes#1044
More about the commit:
Added some missing "varout" typemaps for Ocaml which was falling back to
use "out" typemaps as they were missing.
Ruby std::set fix for SwigValueWrapper C++11 changes.
This is necessary for regex-like renames (where you can't use the #define trick
as is done in many of the %keywordwarn directives). It's now unnecessary to print
the "renaming to '`x`'" code explicitly by the kw.swg files.
Remove redundant NULL checks before free()/delete
The ISO C and C++ standards guarantee that it's safe to call these
on a NULL pointer, so it's not necessary for the calling code to
also check.
Fixes https://sourceforge.net/p/swig/feature-requests/70/
For users who have typemaps for the parameters in the setElement method.
Correct definitions of const_reference to match the those in the
(C++11) standard.
Added to the javadestruct, javadestruct_derived, ddispose, ddispose_derived
typemaps to mirror enhanced flexibility in the csdisposing and
csdisposing_derived (C#) typemaps. If provided the contents are generated
as the delete/dispose method's parameters declaration.
Tests for std::vector of pointers added which check
std::vector<T*>::const_reference and std::vector<T*>::reference
usage which gave compilation errors in Python and Perl which had
specialized these vectors incorrectly.
The director c++ exceptions are thrown in a helper method instead of in
the director overloaded method. This circumvents compiler warnings about
throwing exceptions when the method has an exception specification or
noexcept. If the exception is thrown, abort will still be called!
In Java, the "director:noexcept" typemap can be used to do something
else. This typemap should be ported to the other languages too.
1) The %extend directive can now optionally support one of the 'class', 'struct' or 'union'.
2) The SWIG library no longer uses the javatype, dtype or cstype typemaps, thereby
completely freeing them up for users to use without having to replicate the library
code that they previously added
Tested by changes to test: java_lib_arrays
The original code was ported from the C# module. It looks like it
tried to avoid reading TLS data by using a shared counter. However,
without also synchronizing on the counter check (or using atomics)
the code is racy. While the races might be benign (the thread that
sets the exception also increments the counter, so when there is
actually an exception, the visible value will always be non-zero
even if it is outdated), they are still undefined behavior,
strictly speaking. Additionally, just using TLS isn't expensive
either.
There might be other cases where this happens when $dclassname
is used for code emitted into the proxy class itself, but so
far, there are none in the test suite or any bug reports.
clang++ using -stdlib=libc++ defines const_reference as a class,
to map boolean vectors onto a bit set. Because swig does
not "see" the type as "const &" it generates incorrect code for this case,
generating a declaration like:
const_reference result;
When const_reference is a typedef to 'bool' as is the case with stdlibc++
this works. When this is actually a constant reference, this is clearly
invalid since it is not initialized. For libc++, this is a class
which cannot be default constructed, resulting in an error. The fix
is to explicitly define the various accessor extensions as having a
bool return type for this specialization.
