This can be used for in-place initialization of non-moveable types.
For compilers that don't support variadic templates, only up to four
arguments are supported. We can always add more, of course, but this
should be good enough until we move to a later MSVC that has full
support for variadic templates.
Inspired by std::experimental::optional from the "Library Fundamentals" C++ TS.
Reviewed by David Blaikie.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218732 91177308-0d34-0410-b5e6-96231b3b80d8
This takes a single argument convertible to T, and
- if the Optional has a value, returns the existing value,
- otherwise, constructs a T from the argument and returns that.
Inspired by std::experimental::optional from the "Library Fundamentals" C++ TS.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218618 91177308-0d34-0410-b5e6-96231b3b80d8
subsequent changes are easier to review. About to fix some layering
issues, and wanted to separate out the necessary churn.
Also comment and sink the include of "Windows.h" in three .inc files to
match the usage in Memory.inc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198685 91177308-0d34-0410-b5e6-96231b3b80d8
As far as simplify_type is concerned, there are 3 kinds of smart pointers:
* const correct: A 'const MyPtr<int> &' produces a 'const int*'. A
'MyPtr<int> &' produces a 'int *'.
* always const: Even a 'MyPtr<int> &' produces a 'const int*'.
* no const: Even a 'const MyPtr<int> &' produces a 'int*'.
This patch then does the following:
* Removes the unused specializations. Since they are unused, it is hard
to know which kind should be implemented.
* Make sure we don't drop const.
* Fix the default forwarding so that const correct pointer only need
one specialization.
* Simplifies the existing specializations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178147 91177308-0d34-0410-b5e6-96231b3b80d8
This implementation of NoneType/None does have some holes but I haven't
found one that doesn't - open to improvement.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175696 91177308-0d34-0410-b5e6-96231b3b80d8
This generalizes Optional to require less from the T type by using aligned
storage for backing & placement new/deleting the T into it when necessary.
Also includes unit tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175580 91177308-0d34-0410-b5e6-96231b3b80d8
Fixes Valgrind failures and removes bitwise operations that don't provide any benefit.
Valgrind failures reported by NAKAMURA Takumi.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171413 91177308-0d34-0410-b5e6-96231b3b80d8
Rationale:
1) This was the name in the comment block. ;]
2) It matches Clang's __has_feature naming convention.
3) It matches other compiler-feature-test conventions.
Sorry for the noise. =]
I've also switch the comment block to use a \brief tag and not duplicate
the name.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168996 91177308-0d34-0410-b5e6-96231b3b80d8
references from whether it supports an R-value reference *this. No
version of GCC today supports the latter, which breaks GCC C++11
compiles of LLVM and Clang now.
Also add doxygen comments clarifying what's going on here, and update
the usage in Optional. I'll update the usages in Clang next.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168993 91177308-0d34-0410-b5e6-96231b3b80d8
This expands to '&', and is intended to be used when an /optional/ rvalue
override is available.
Before:
void foo() const { ... }
After:
void foo() const LLVM_LVALUE_FUNCTION { ... }
void foo() && { ... }
This is used to allow moving the contents of an Optional.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168963 91177308-0d34-0410-b5e6-96231b3b80d8
This allows llvm::Optional to be used with movable-but-not-copyable types.
While LLVM itself is still C++03, there's no reason why tools built on
top of it can't use C++11 features.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166241 91177308-0d34-0410-b5e6-96231b3b80d8
objects, since they'll end up using the implicit conversion to "bool"
and causing some very "fun" surprises.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125380 91177308-0d34-0410-b5e6-96231b3b80d8
