Many `Type`s can correspond to the same `CType`, so this reduces the
number of used locals by 27760 when compiling only-c.
Also, disabled some tests that were only passing by accident and
shouldn't really be considered working.
* Implement @fieldParentPtr on a union
* Refactor field access to ensure that it is handled consistently
* Remove `renderTypecast` as it is now behaves the same as `renderType`
One of the main points of for loops is that you can safety check the
length once, before entering the loop, and then safely assume that every
element inside the loop is in bounds.
In master branch, the safety checks are incorrectly intact even inside
for loops. This commit fixes it. It's especially nice with multi-object
loops because the number of elided checks is N * M where N is how many
iterations and M is how many objects.
These functions are currently footgunny when working with pointers to
arrays and slices. They just return the stated length of the array/slice
without iterating and looking for the first sentinel, even if the
array/slice is a sentinel terminated type.
From looking at the quite small list of places in the standard
library/compiler that this change breaks existing code, the new code
looks to be more readable in all cases.
The usage of std.mem.span/len was totally unneeded in most of the cases
affected by this breaking change.
We could remove these functions entirely in favor of other existing
functions in std.mem such as std.mem.sliceTo(), but that would be a
somewhat nasty breaking change as std.mem.span() is very widely used for
converting sentinel terminated pointers to slices. It is however not at
all widely used for anything else.
Therefore I think it is better to break these few non-standard and
potentially incorrect usages of these functions now and at some later
time, if deemed worthwhile, finally remove these functions.
If we wait for at least a full release cycle so that everyone adapts to
this change first, updating for the removal could be a simple find and
replace without needing to worry about the semantics.
