Summary:
The const_cast in the "const" version of TakeExpected was quite
dangerous, as the function does indeed modify the apparently const
argument.
I assume the reason the const overload was added was to make the
function bind to xvalues(temporaries). That can be also achieved with
rvalue references, so I use that instead.
Using the ASSERT macros on const Expected objects will now become
illegal, but I believe that is correct, as it is not actually possible
to inspect the error stored in an Expected object without modifying it.
Reviewers: zturner, chandlerc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34405
llvm-svn: 306001
Many times unit tests for different libraries would like to use
the same helper functions for checking common types of errors.
This patch adds a common library with helpers for testing things
in Support, and introduces helpers in here for integrating the
llvm::Error and llvm::Expected<T> classes with gtest and gmock.
Normally, we would just be able to write:
EXPECT_THAT(someFunction(), succeeded());
but due to some quirks in llvm::Error's move semantics, gmock
doesn't make this easy, so two macros EXPECT_THAT_ERROR() and
EXPECT_THAT_EXPECTED() are introduced to gloss over the difficulties.
Consider this an exception, and possibly only temporary as we
look for ways to improve this.
Differential Revision: https://reviews.llvm.org/D33059
llvm-svn: 305395
