On Friday, 17 July 2015 at 12:43:33 UTC, Martin Nowak wrote:
The assumption that code with attributes is better than code
without attributes is flawed.
- nothrow
Nice, the compiler must not emit exception handling code, but
the real
problem is how bad dmd's EH code is.
https://issues.dlang.org/show_bug.cgi?id=12442
State of the art EH handling is almost "zero cost",
particularly if
compared to other error handling schemes.
nothrow is not only performance, but also semantics.
Yeah, an optimization was planned to not run cleanups on Error,
without it you can't inline cleanups, and nothrow functions can
throw Errors.
- @nogc
Why is this needed on a per function level? If one doesn't
want to use
the GC it could be disabled on a per-thread or per-process
level.
We now have a GC profiler, which is a good tool to find
unwanted
allocations.
Of course we need to change many phobos functions to avoid
allocations, but @nogc doesn't help us to design better APIs.
Hmm, it sounds interesting to make @nogc a language option
instead of function attribute.
- pure
The compiler can reuse the result of a strongly pure function
call,
but compilers can do CSE [ยน] for ages. CSE requires inlining
to determine
whether a function has a sideeffect, but reusing of results
is almost
exclusively useful for functions that are small enough to be
inlined anyhow.
You don't always have the source for the function, and currently
purity needs only the function signature alone. Also a function
attribute allows to enforce purity.
- @safe
Nice idea in theory, but why not do this as a compiler switch
for the
modules being compiled (with an @unsafe {} guard).
The way we do it currently with @trusted/@safe doesn't
guarantee
anything for @trusted/@safe foreign code anyhow.
You mean SafeD allows unsafe code?
