On Saturday, 21 January 2017 at 10:15:46 UTC, ZombineDev wrote:
On Saturday, 21 January 2017 at 09:56:29 UTC, ZombineDev wrote:
On Saturday, 21 January 2017 at 02:47:49 UTC, bitwise wrote:
When std.experimental.allocator was created, I was under the
impression it was meant to be used to make containers. But
since allocate() returns void[], casts are required before
using that memory, which is unsafe.
Is my only option to wrap the casts in an @trusted helper
function? or am I missing something?
Thanks
There's no need for casts. You can just use the high-level
wrappers:
http://dlang.org/phobos-prerelease/std_experimental_allocator#.make
http://dlang.org/phobos-prerelease/std_experimental_allocator#.makeArray
http://dlang.org/phobos-prerelease/std_experimental_allocator#.dispose
http://dlang.org/phobos-prerelease/std_experimental_allocator#.makeMultidimensionalArray
http://dlang.org/phobos-prerelease/std_experimental_allocator#.disposeMultidimensionalArray
Though, since you are implementing a container that manually
manages memory, you won't be able to get away with no @trusted
parts in your code.
http://dlang.org/phobos-prerelease/std_experimental_allocator#.expandArray can help, but you'll still need to call dispose/deallocate somewhere yourself and you're the only that knows when is safe to do this.
If you look at how Rust's standard library is implemented,
you'll see the same pattern. The users have a safe API, but
underneath you'll that the library uses many 'unsafe' blocks
where the compiler doesn't see the full picture which only the
author of the code knows.
I guess you're right. This is my first time looking at @safe in
detail. I figured something like malloc() could @trusted, but I
suppose free cannot.
I pictured being able to use an @safe allocator with an @safe
container. How else could one reliably create @safe containers,
or any @safe object for that matter, that allows the substitution
of arbitrary and possibly unsafe components?
I guess the answer is responsible programming, but that seems
counter intuitive given the goals of @safe.
