Re: Array Indexing/Slicing Range Checking, Exceptions and @nogc
On 30.03.2016 15:44, Nordlöw wrote: On Wednesday, 30 March 2016 at 13:24:20 UTC, ag0aep6g wrote: [...] This is off topic, but don't mark templates like that @trusted. By doing so you also trust R, but you don't know if it's memory safe. Should I post in group "General" instead? No, no, I meant my comment is off topic.
Re: Array Indexing/Slicing Range Checking, Exceptions and @nogc
On Wednesday, 30 March 2016 at 13:38:40 UTC, Adam D. Ruppe wrote: Don't use your ptr method. Instead, make it a slice method: `return _store[0 .. _length];` Now you can just index it internally and let the compiler automatically insert range checks. When you need the pointer, you still have slice.ptr. So punt the problem to the compiler. This will also ensure you always use it correctly too. Superb! Thanks.
Re: Array Indexing/Slicing Range Checking, Exceptions and @nogc
On Wednesday, 30 March 2016 at 13:24:20 UTC, ag0aep6g wrote:
On 30.03.2016 15:12, Nordlöw wrote:
https://github.com/nordlow/justd/blob/master/packedarray.d
From there:
this(R)(R values, bool assumeSortedParameter = false)
@trusted nothrow @("complexity", "O(n*log(n))")
if (isInputRange!R)
This is off topic, but don't mark templates like that @trusted.
By doing so you also trust R, but you don't know if it's memory
safe.
Should I post in group "General" instead?
Re: Array Indexing/Slicing Range Checking, Exceptions and @nogc
On Wednesday, 30 March 2016 at 13:12:49 UTC, Nordlöw wrote: I'm however uncertain about how to implement error handling of bounds checking and how these interact with `@nogc`. My main goal is to match semantics of builtin D arrays and slices. I would actually cheat on this somehow and actually, there's a better way entirely: Don't use your ptr method. Instead, make it a slice method: `return _store[0 .. _length];` Now you can just index it internally and let the compiler automatically insert range checks. When you need the pointer, you still have slice.ptr. So punt the problem to the compiler. This will also ensure you always use it correctly too. If you don't want to do that, you could cheat on the range error a couple other ways too: 1) define a function to allocate the exception that lies about being nogc. It is an Error and unrecoverable anyway - you are allowed to throw them from nothrow too! 2) Define a fake slice and index into it, knowing it is out of bounds so the compiler generates the error. Dangerous in -release mode though! 3) Pre-allocate a RangeError object. Meh, I wouldn't do that, but listing it because you could.
Re: Array Indexing/Slicing Range Checking, Exceptions and @nogc
On 30.03.2016 15:12, Nordlöw wrote:
https://github.com/nordlow/justd/blob/master/packedarray.d
From there:
this(R)(R values, bool assumeSortedParameter = false) @trusted nothrow
@("complexity", "O(n*log(n))")
if (isInputRange!R)
This is off topic, but don't mark templates like that @trusted. By doing
so you also trust R, but you don't know if it's memory safe.
