Either not returning *this, or in the case of Variant, not checking for
self assignment. In AK::Atomic, we can't return *this due to the wrapper
semantics Atomic implements.
By replacing MakeUnsigned<Source> in this specific specialization with a
simple negativity check this now works for floating point source types.
Previously it would attempt a comparison of the destination type and
void.
These were already implicitly required to be integral via the usage of
the is_within_range templated function, but making them explicit should
produce nicer error messages when building, and make the IDE highlight
the incorrect usage.
(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED)
Since all of these checks are done in release builds as well,
let's rename them to VERIFY to prevent confusion, as everyone is
used to assertions being compiled out in release.
We can introduce a new ASSERT macro that is specifically for debug
checks, but I'm doing this wholesale conversion first since we've
accumulated thousands of these already, and it's not immediately
obvious which ones are suitable for ASSERT.
Problem:
- `constexpr` functions are decorated with the `inline` specifier
keyword. This is redundant because `constexpr` functions are
implicitly `inline`.
- [dcl.constexpr], §7.1.5/2 in the C++11 standard): "constexpr
functions and constexpr constructors are implicitly inline (7.1.2)".
Solution:
- Remove the redundant `inline` keyword.
Problem:
- `Checked` is not `constexpr`-aware.
Solution:
- Decorate member functions with `constexpr` keyword.
- Add tests to ensure the functionality where possible.
Problem:
- Compiler-generated functions are being defined which results in
extra code to maintain.
Solution:
- Switch to compiler-generated default functions for default
construction, copy assignment, move assignment, copy construction
and move construction.
Specifically:
- post-increment actually implemented pre-increment
- helper-templates that provided operator{+,-,*,/}() couldn't possibly work,
because the interface of add (etc) were incompatible (not taking a Checked<>,
and returning void)
And switch the two-argument version of Checked::multiplication_would_overflow()
to use __builtin_mul_overflow_p(). This helps GCC optimize the code better.
