Re: Why this compiles?
On Sunday, 26 November 2023 at 21:45:21 UTC, Antonio wrote: In this example, ```a``` and ```b``` vars are not of the same type and don't implement the same interface. **why ```assert(a==b)``` compiles?** They're both subclasses of Object and inherit a generic opEquals from that base.
Why this compiles?
In this example, ```a``` and ```b``` vars are not of the same
type and don't implement the same interface. **why
```assert(a==b)``` compiles?**
```d
interface IOpt(T) {
bool opEquals(const IOpt!T) const @safe pure;
}
class None(T) : IOpt!T {
bool opEquals(const IOpt!T other) const @safe pure => true;
}
void main() {
auto a = new None!int();
auto b = new None!string();
assert(a==b);
}
```
Re: mixin under -betterC
On Thursday, 23 November 2023 at 16:33:52 UTC, DLearner wrote:
Code below is intended to test simple mixin with lambda
function under -betterC.
Works with full-D, but fails with 'needs GC' errors under
-betterC.
Why is this so, bearing in mind the concatenations are executed
at
compile, not run, time?
```
// Test harness
extern(C) void main() {
import core.stdc.stdio : printf;
import testmod;
bool FirstVarGreater;
int Var_A = 4;
int Var_B = 3;
FirstVarGreater = mixin(mxnTest("Var_A", "Var_B"));
if (FirstVarGreater) {
printf("First Var is Greater\n");
} else {
printf("First Var is not Greater\n");
}
}
// testmod
string mxnTest(string strVar1, string strVar2) {
return `(int Var1, int Var2) {
if (Var1 > Var2) {
return true;
} else {
return false;
}
}(` ~ strVar1 ~ `,` ~ strVar2 ~ `)`;
}
```
You've been explained the reason why that does not work, note
however that it's not hopeless see
-
https://forum.dlang.org/thread/ahqnylrdftmmvtyvo...@forum.dlang.org
- https://github.com/dlang/dmd/pull/15636
unfortunately the PR is stalled since two months.
Re: Compiling an app to a single binary - possible?
Theoretically possible but not really expected to and generally does not give you much over simply distributing an archive. I'd even discourage it because it makes impossible to delegate handling of static assets to reverse proxy like nginx (which is likely to do better job at it being specialized tool) Is vibe-powered backend app really runs notably slower then `nginx` when serving static files? I looked on D lang in web backend as a great alternative for mainstream servers such as `nginx` etc especially with its ability to serve files the the same rates or even more faster. Not for a large sites but mostly embedded application such as vending machines with local-only web interface, or powerful SOHO routers and home automation controllers. Putting all files into an executable also makes it available directly from RAM without any caching, so `sendfile` syscall can be just run for them with direct data pointer, almost without impacting on the app does anything else.
Re: mixin under -betterC
On Thursday, 23 November 2023 at 16:33:52 UTC, DLearner wrote:
string mxnTest(string strVar1, string strVar2) {
return `(int Var1, int Var2) {
if (Var1 > Var2) {
return true;
} else {
return false;
}
}(` ~ strVar1 ~ `,` ~ strVar2 ~ `)`;
}
```
This function exists at runtime. Another module could, in theory,
import it and call it. A shared library could, in theory, export
it. You used it at compile time, but the function is available
for other users too.
betterC doesn't know the difference between theory and practice.
Re: mixin under -betterC
On Thursday, 23 November 2023 at 17:02:58 UTC, Paul Backus wrote: [...] This is a known limitation: https://issues.dlang.org/show_bug.cgi?id=23637 [...] Sorry to come back to this, but the reference above suggests _not_ a bug in the compiler. If not a bug in the compiler, please, what is going on? I repeat that the only possible trigger I see for the GC are the ~ that happen at compile, not run, time.
Re: msghdr and cmsghdr mismatch for alpine musl
On Saturday, 25 November 2023 at 05:04:57 UTC, d007 wrote: `import core.sys.posix.sys.socket : msghdr, cmsghdr, iovec;` `msg_iovlen`, `msg_controllen`, `cmsg_len` is ulong for x86-64 in druntime. in alpine musl, they are int, socklen_t(uint), socklen_t(uint). Is this mismatch can cause problems is I use related api ? Yes. Mismatch of types is a really bad error for c interaction. -Steve
