Bug 19572 – std.array.Appender.put invokes struct constructor via cast

Repro: struct Struct { private int key_; public int fun() const { return 23; } alias fun this; } void main() { import std.array : Appender; Appender!(Struct[]) appender; appender.put(const(Struct)(42)); auto result = appender.data[0]; assert(result.key_ != 23); } What happens is that Appender checks that it can convert const(Struct) implicitly to Struct, but it does so via cast(Struct), which then invokes Struct(const(Struct).fun) implicitly. Appender should cast() its parameter, then rely on implicit conversion to do the rest.

Fixed in 2.085.0: constness-casts no longer implicitly call the struct constructor.