Bug 17387 – static struct this(ref) not pure

struct S { this(ref int val) { ++val; } } pure unittest { int val = 3; auto s = S(val); assert(val == 4); } The above fails to compile with dmd v2.074.0: purestaticstruct.d(6): Error: pure function 'purestaticstruct.__unittestL3_1' cannot call impure constructor 'purestaticstruct.S.this' If the struct is moved inside the unittest, it compiles as expected.

You have to mark the constructor as `pure`: struct S { this(ref int val) pure { ++val; } } Attributes are only inferred under special circumstances. You generally have to be explicit with them. Closing as invalid. Please reopen if I'm missing the point.

Yes, thanks. What I was confused by was actually when the struct is defined inside the unittest with the static keyword - pure is not inferred. Non-static nested struct inference works, it seemed weird that adding static prevents inference. But obviously the compiler treats it the same as the code in comment 0.