October 14, 2019
https://issues.dlang.org/show_bug.cgi?id=20300

          Issue ID: 20300
           Summary: memoize doesn't work with default params
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Linux
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: phobos
          Assignee: nobody@puremagic.com
          Reporter: trikkuz@gmail.com

import std;

int test(int a = 0) { return a; }

alias cached = memoize!test;

void main()
{
    cached(0); // Works;
    cached(1); // Works;
    cached();  // Error
}


Error: function std.functional.memoize!(test).memoize(int _param_0) is not
callable using argument types ()
onlineapp.d(11):        missing argument for parameter #1: int _param_0

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