https://issues.dlang.org/show_bug.cgi?id=20474

          Issue ID: 20474
           Summary: Deprecation warnings inside deprecated function
                    template
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: normal
          Priority: P1
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: moonlightsentinel@disroot.org

DMD issues deprecation warnings when compiling the following programm:

---------------

deprecated struct S {}

deprecated void foo()(S par)
{
    S var;
}

deprecated void main()
{
    foo(S.init);
}

---------------

onlineapp.d(3): Deprecation: struct onlineapp.S is deprecated
onlineapp.d(3): Deprecation: struct onlineapp.S is deprecated

---------------

It wont produce any warnings if foo is a normal function instead of a template.

The duplicate warning is another issue probably related to 20467

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