Classes will automatically inherit the virtual-ness of their base
class destructors. If the base class already has a virtual
destructor and the derived class needs default destructor semantics
then the derived class can omit defining the destructor in favor of
the compiler automatically defining it.
This has an additional benefit of reenabling move semantics. The
presence of a user-specified destructor automatically disables move
operations.
This is the recommended way of adding new Opts in our documentation
for using custom main, but we did not compile the code to see if it
works. We now compile the example as part of the BUILD_EXAMPLES
option.
Fixes#2787
This removes about 200 pointless copies from printing the help
message (the original motivation for the change), and also nicely
improves performance of the various reporters that depend on
TextFlow.
The code is now even worse mess than before, due to the ad-hoc
implementation of Result-ish type based on virtual functions in
Clara, but it has dropped the allocations for empty binary down
to 151.
Because TokenStream is copied around a lot, moving it to use
`StringRef` removes _a lot_ of allocations per `Opt` in the parser.
Args are not copied around much, but changing them as well makes it
obvious that they do not participate in the ownership.
The changes add up to removing ~180 allocations for "empty"
invocation of the test binary.
(`./tests/ExtraTests/NoTests --allow-running-no-tests -o /dev/null`
is down to 317 allocs)
This prevents the full construction from being O(N^2) in number
of `Opt`s, and also reduces the number of allocations for running
no tests significantly:
`tests/SelfTest`: 7705 -> 6095
`tests/ExtraTests/NoTests` 2215 -> 605
* Clara::Opt::getHelpColumns returns single item
It could never return multiple items, but for some reason it
was wrapping that single item in a vector.
* Use ReusableStringStream in Clara
* Reserve HelpColumns ahead of time
* Use StringRef for descriptions in HelpColumn type
The combination of these changes ends up removing about 7% (~200)
of allocations when Catch2 has to prepare output for `-h`.
There is no good reason for these to be std::strings, as these
are just (optional) constants for nice user output. This ends up
reducing the allocations significantly.
When measuring allocations when running no tests, the changes are
`tests/SelfTest` 9213 -> 7705
`tests/ExtraTests/NoTests` 3723 -> 2215
By moving to use our `uniform_integer_distribution`, which is
reproducible across different platforms, instead of the stdlib
one which is not, we can provide reproducible results for `float`s
and `double`s. Still no reproducibility for `long double`s, because
those are too different across different platforms.
* Utility for extended mult n x n bits -> 2n bits
* Utility to adapt output from URBG to target (unsigned) integral
type
* Utility to reorder signed values into unsigned type while keeping
the order.
Specifically we add
* `gamma(a, b)`, which returns the magnitude of largest 1-ULP
step in range [a, b].
* `count_equidistant_float(a, b, distance)`, which returns the
number of equi-distant floats in range [a, b].
