c# - Optional parameters on delegates doesn't work properly -

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this question has answer here:

why piece of code not compile? 

delegate int xxx(bool x = true);  xxx test = f;  int f() {    return 4; }

optional parameters use on calling side - not on single-method-interface implementation. example, should compile:

delegate void simpledelegate(bool x = true);  static void main() {     simpledelegate x = foo;     x(); // print "true" }  static void foo(bool y) {     console.writeline(y); }

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