https://issues.dlang.org/show_bug.cgi?id=24147
Issue ID: 24147
Summary: Struct destructors should not allow GC
Product: D
Version: D2
Hardware: x86_64
OS: Linux
Status: NEW
Severity: enhancement
Priority: P1
Component: dmd
Assignee: nob...@puremagic.com
Reporter: la...@lancebachmeier.com
It is possible to do things like string concatenation inside a destructor. That
shouldn't be allowed to compile because it is not valid code. The compiler
should treat destructors as @nogc whether they're marked that way or not.
Example code:
import std.stdio;
struct Predictable
{
string id;
this(string _id)
{
writeln("Constructor ", _id);
id = _id;
}
~this()
{
writeln("Destructor " ~ id);
}
}
void main()
{
Predictable[] result;
result ~= Predictable("1");
writeln("result: ", result);
}
Dies with
Constructor 1
result: [Predictable("1")]
core.exception.InvalidMemoryOperationError@src/core/lifetime.d(126): Invalid
memory operation
Putting @nogc on the destructor, the compiler gives this message:
onlineapp.d(12): Error: `@nogc` destructor `onlineapp.Predictable.~this` cannot
call non-@nogc function `std.stdio.writeln!string.writeln`
/dlang/dmd/linux/bin64/../../src/phobos/std/stdio.d(4251): which calls
`std.stdio.trustedStdout`
onlineapp.d(12): Error: cannot use operator `~` in `@nogc` destructor
`onlineapp.Predictable.~this`
https://run.dlang.io/is/7fZepu
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