However, there's a problem on both GCC and Clang: they can't mangle
`__is_same(T,U)` if it appears anywhere that affects mangling. That's
a hard error. And it turns out that GCC puts dependent return types
into the mangling more aggressively than Clang, so for GCC's benefit
we need to avoid using raw `_IsSame` in the return type of
`swap(tuple&, tuple&)`. Therefore, make `__all` into a named type
instead of an alias.
If we ever need to support a compiler without the __is_same builtin,
we can make this an alias template for `is_same<T,U>::type`.
Differential Revision: https://reviews.llvm.org/D115100
Clang used to support [[nodebug]] everywhere except on typedefs. Since
we don't support such old Clangs anymore, we can get rid of _LIBCPP_NODEBUG_TYPE
in favour of always using _LIBCPP_NODEBUG.
Differential Revision: https://reviews.llvm.org/D108996
The new meta-programming primitives are lower cost than the old versions. This patch removes those old versions and switches libc++ to use the new ones.
llvm-svn: 364160
When applied to a typedef or alias template, the [[nodebug]] attribute
makes the typedef transparent to the debugger, so instead of seeing
`std::__function::__alloc_func<remove_reference<void(&)()>::type,
allocator<remove_reference<void(&)()>, void()>::_Target` you see
`void(&)()` as the type of the variable in your debugger.
Removing all this SFINAE noise from debug info has huge binary size
wins, in addition to improving the readability.
For now this change is on by default. Users can override it by
specifying -D_LIBCPP_NODEBUG_TYPE=
llvm-svn: 363117
to reflect the new license. These used slightly different spellings that
defeated my regular expressions.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351648
The name _LIBCPP_TYPE_VIS_ONLY is no longer accurate because both
_LIBCPP_TYPE_VIS and _LIBCPP_TYPE_VIS_ONLY expand to
__attribute__((__type_visibility__)) with Clang. The only remaining difference
is that _LIBCPP_TYPE_VIS_ONLY can be applied to templates whereas
_LIBCPP_TYPE_VIS cannot (due to dllimport/dllexport not being allowed on
templates).
This patch renames _LIBCPP_TYPE_VIS_ONLY to _LIBCPP_TEMPLATE_VIS.
llvm-svn: 291035
Summary:
This patch attempts to re-implement a fix for LWG 2770, but not the actual specified PR.
The PR for 2770 specifies tuple_size<T const> as only conditionally providing a `::value` member. However C++17 structured bindings require `tuple_size<T const>` to be complete only if `tuple_size<T>` is also complete. Therefore this patch implements only provides the specialization `tuple_size<T CV>` iff `tuple_size<T>` is a complete type.
This fixes http://llvm.org/PR31513.
Reviewers: mclow.lists, rsmith, mpark
Subscribers: mpark, cfe-commits
Differential Revision: https://reviews.llvm.org/D28222
llvm-svn: 291019
This patch implements the correct PR for LWG 2770. It also makes the primary
tuple_size template incomplete again which fixes part of llvm.org/PR31513.
llvm-svn: 290846
This patch reverts the changes to tuple which fixed construction from
types derived from tuple. It breaks the code mentioned in llvm.org/PR31384.
I'll follow this commit up with a test case.
llvm-svn: 289773
Summary:
The standard requires tuple have the following constructors:
```
tuple(tuple<OtherTypes...> const&);
tuple(tuple<OtherTypes...> &&);
tuple(pair<T1, T2> const&);
tuple(pair<T1, T2> &&);
tuple(array<T, N> const&);
tuple(array<T, N> &&);
```
However libc++ implements these as a single constructor with the signature:
```
template <class TupleLike, enable_if_t<__is_tuple_like<TupleLike>::value>>
tuple(TupleLike&&);
```
This causes the constructor to reject types derived from tuple-like types; Unlike if we had all of the concrete overloads, because they cause the derived->base conversion in the signature.
This patch fixes this issue by detecting derived types and the tuple-like base they are derived from. It does this by creating an overloaded function with signatures for each of tuple/pair/array and checking if the possibly derived type can convert to any of them.
This patch fixes [PR17550]( https://llvm.org/bugs/show_bug.cgi?id=17550)
This patch
Reviewers: mclow.lists, K-ballo, mpark, EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D27606
llvm-svn: 289727
Summary:
Currently a number of GCC warnings are emitted when building libc++. This patch fixes or ignores all of them. The primary changes are:
* Work around strict aliasing issues in `typeinfo::hash_code()` by using __attribute__((may_alias)). However I think a non-aliasing `hash_code()` implementation is possible. Further investigation needed.
* Add `_LIBCPP_UNREACHABLE()` to switch in `strstream.cpp` to avoid -Wpotentially-uninitialized.
* Fix -Wunused-value warning in `__all` by adding a void cast.
* Ignore -Wattributes for now. There are a number of real attribute issues when using GCC but enabling the warning is too noisy.
* Ignore -Wliteral-suffix since it warns about the use of reserved identifiers. Note Only GCC 7.0 supports disabling this warning.
* Ignore -Wc++14-compat since it warns about the sized new/delete overloads.
Reviewers: EricWF
Differential Revision: https://reviews.llvm.org/D24003
llvm-svn: 280007
This patch is the last in a series that replaces recursive meta-programming
in std::tuple with non-recursive implementations.
Previously std::tuple could only be instantiated with 126 elements before
it blew the max template instantiation depth. Now the size of std::tuple is
essentially unbounded (I've tested with over 5000 elements).
One unfortunate side-effect of this change is that tuple_constructible
and similar no longer short circuit after the first failure. Instead they
evaluate the conditions for all elements. This could be potentially breaking.
I plan to look into this further.
llvm-svn: 274331
This patch attempts to improve the QoI of std::tuples tuple_element and
__make_tuple_types helpers. Previously they required O(N) instantiations,
one for every element in the tuple
The new implementations are O(1) after __tuple_indices<Id...> is created.
llvm-svn: 274330
The previous __make_tuple_indices implementation caused O(N) instantiations
and was pretty inefficient. The C++14 __make_integer_sequence implementation
is much better, since it either uses a builtin to generate the sequence or
a very nice Log8(N) implementation provided by richard smith.
This patch moves the __make_integer_sequence implementation into __tuple
and uses it to implement __make_tuple_indices.
Since libc++ can't expose the name 'integer_sequence' in C++11 this patch
also introduces a dummy type '__integer_sequence' which is used when generating
the sequence. One the sequence is generated '__integer_sequence' can be
converted into the required type; either '__tuple_indices' or 'integer_sequence'.
llvm-svn: 274286
Summary:
There is no reason to guard `tuple_size`, `tuple_element` and `get<I>(...)` for pair and array inside of `<__tuple>` so that they are only available when we have variadic templates.
This requires there be redundant declarations and definitions. It also makes it easy to get things wrong.
For example the following code should compile (and does in c++11).
```
#define _LIBCPP_HAS_NO_VARIADICS
#include <array>
int main()
{
static_assert((std::tuple_size<std::array<int, 10> volatile>::value == 10), "");
}
```
This patch lifts the non-variadic parts of `tuple_size`, `tuple_types`, and `get<I>(...)` to the top of `<__tuple>` where they don't require variadic templates. This patch also removes `<__tuple_03>` because there is no longer a need for it.
Reviewers: danalbert, K-ballo, mclow.lists
Reviewed By: mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D7774
llvm-svn: 232492
Summary:
http://llvm.org/bugs/show_bug.cgi?id=18345
Tuple's constructor and assignment operators for "tuple-like" types evaluates __make_tuple_types unnecessarily. In the case of a large array this can blow the template instantiation depth.
Ex:
```
#include <array>
#include <tuple>
#include <memory>
typedef std::array<int, 1256> array_t;
typedef std::tuple<array_t> tuple_t;
int main() {
array_t a;
tuple_t t(a); // broken
t = a; // broken
// make_shared uses tuple behind the scenes. This bug breaks this code.
std::make_shared<array_t>(a);
}
```
To prevent this from happening we delay the instantiation of `__make_tuple_types` until after we perform the length check. Currently `__make_tuple_types` is instantiated at the same time that the length check .
Test Plan: Two tests have been added. One for the "tuple-like" constructors and another for the "tuple-like" assignment operator.
Reviewers: mclow.lists, EricWF
Reviewed By: EricWF
Subscribers: K-ballo, cfe-commits
Differential Revision: http://reviews.llvm.org/D4467
llvm-svn: 220769
Arthur O'Dwyer