• d-bugmail puremagic.com (29/29) Sep 04 2021 https://issues.dlang.org/show_bug.cgi?id=22278

d-bugmail puremagic.com writes:

https://issues.dlang.org/show_bug.cgi?id=22278

          Issue ID: 22278
           Summary: [Conditional Compilation] there should be in and out
                    flags
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Linux
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: dmd
          Assignee: nobody puremagic.com
          Reporter: jlourenco5691 gmail.com

Currently, there is no way within the language to check if contracts are being
compiled or not. The only way is to use `version(assert)`, which accomplishes
that in a way. The problem is if the user runs unit tests in release mode. The
assertions are compiled but contracts are not, leading to the failure of all
`assertThrown` checks.

There are ways to still compile without failures. DMD has the `check` flag that
can override the build mode. To run unit tests in release with `in` contracts
on, one can pass `-check=in=on` to the compiler. But this still isn't favorable
because the flag isn't shared across compilers. LDC for example has
`--enable-preconditions=1`.

Having a language version can standardize this and make it easier when working
with this.

I propose implementing the version flags: D_PreConditions and D_PostConditions
for `in` and `out` contracts respectively.

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