dmd/compiler/test/fail_compilation/diag12124.d

/*
TEST_OUTPUT:
---
fail_compilation/diag12124.d(14): Error: struct `diag12124.S1` `static opCall` is hidden by constructors and can never be called
fail_compilation/diag12124.d(14):        Please use a factory method instead, or replace all constructors with `static opCall`.
fail_compilation/diag12124.d(20): Error: struct `diag12124.S2` `static opCall` is hidden by constructors and can never be called
fail_compilation/diag12124.d(20):        Please use a factory method instead, or replace all constructors with `static opCall`.
---
*/

struct S1
{
    this(int) {}
    static S1 opCall() { assert(0); }
}

struct S2
{
    this(int) {}
    static S2 opCall()() { assert(0); }
}