Re: How to use core.vararg to print D variadic arguments and their types without using ! (template instantiation)?
Note that this doesn't work in gdc. The templated version is actually more akin to what C does. Yeah it does not seem to work in gdc when tested using https://d.godbolt.org/ The errors produced: ``` :11:12: error: none of the overloads of template 'core.stdc.stdarg.va_arg' are callable using argument types '!()(__va_list_tag[1], TypeInfo, int*)' 11 | va_arg(_argptr, typeid(i), &i); |^ /opt/compiler-explorer/gcc-trunk-20230917/lib/gcc/x86_64-linux-gnu/14.0.0/include/d/core/stdc/stdarg.d:179:7: note: Candidates are: 'va_arg(T)(ref va_list ap)' 179 | T va_arg(T)(ref va_list ap); // intrinsic | ^ /opt/compiler-explorer/gcc-trunk-20230917/lib/gcc/x86_64-linux-gnu/14.0.0/include/d/core/stdc/stdarg.d:291:10: note: 'va_arg(T)(ref va_list ap, ref T parmn)' 291 | void va_arg(T)(ref va_list ap, ref T parmn); // intrinsic | ^ :14:12: error: none of the overloads of template 'core.stdc.stdarg.va_arg' are callable using argument types '!()(__va_list_tag[1], TypeInfo, double*)' 14 | va_arg(_argptr, typeid(d), &d); |^ /opt/compiler-explorer/gcc-trunk-20230917/lib/gcc/x86_64-linux-gnu/14.0.0/include/d/core/stdc/stdarg.d:179:7: note: Candidates are: 'va_arg(T)(ref va_list ap)' 179 | T va_arg(T)(ref va_list ap); // intrinsic | ^ /opt/compiler-explorer/gcc-trunk-20230917/lib/gcc/x86_64-linux-gnu/14.0.0/include/d/core/stdc/stdarg.d:291:10: note: 'va_arg(T)(ref va_list ap, ref T parmn)' 291 | void va_arg(T)(ref va_list ap, ref T parmn); // intrinsic | ^ ASM generation compiler returned: 1 :11:12: error: none of the overloads of template 'core.stdc.stdarg.va_arg' are callable using argument types '!()(__va_list_tag[1], TypeInfo, int*)' 11 | va_arg(_argptr, typeid(i), &i); |^ /opt/compiler-explorer/gcc-trunk-20230918/lib/gcc/x86_64-linux-gnu/14.0.0/include/d/core/stdc/stdarg.d:179:7: note: Candidates are: 'va_arg(T)(ref va_list ap)' 179 | T va_arg(T)(ref va_list ap); // intrinsic | ^ /opt/compiler-explorer/gcc-trunk-20230918/lib/gcc/x86_64-linux-gnu/14.0.0/include/d/core/stdc/stdarg.d:291:10: note: 'va_arg(T)(ref va_list ap, ref T parmn)' 291 | void va_arg(T)(ref va_list ap, ref T parmn); // intrinsic | ^ :14:12: error: none of the overloads of template 'core.stdc.stdarg.va_arg' are callable using argument types '!()(__va_list_tag[1], TypeInfo, double*)' 14 | va_arg(_argptr, typeid(d), &d); |^ /opt/compiler-explorer/gcc-trunk-20230918/lib/gcc/x86_64-linux-gnu/14.0.0/include/d/core/stdc/stdarg.d:179:7: note: Candidates are: 'va_arg(T)(ref va_list ap)' 179 | T va_arg(T)(ref va_list ap); // intrinsic | ^ /opt/compiler-explorer/gcc-trunk-20230918/lib/gcc/x86_64-linux-gnu/14.0.0/include/d/core/stdc/stdarg.d:291:10: note: 'va_arg(T)(ref va_list ap, ref T parmn)' 291 | void va_arg(T)(ref va_list ap, ref T parmn); // intrinsic | ^ Execution build compiler returned: 1 ```
container vs standard array
Hi All,
I am trying to understand as to why the below code is throwing
error
Code
```
import std.stdio: writeln;
import std.container.array;
void main () {
//auto a = Array!string("Aname"); // throws error
auto b = Array!char("Bname");// works
auto c = Array!string("Aname", "Bname"); // works
//writeln(a);
writeln("Container Array :", b);
writeln("Container Array :", c);
writeln();
string[] d = ["Dname"]; // works
string[] e = ["Dname", "Ename"]; // works
writeln("Standard Array :", d);
writeln("Standard Array :", e);
}
```
From,
Vino
Which function returns a pair after division ? (integer,frac)
What D function or D operator does this? ```asm IDIV EAX, r/m32 ``` ``` IDIV 5, 2 EAX = 2 EDX = 1 ``` and returns (2,1) at once?
Re: Which function returns a pair after division ? (integer,frac)
On Tuesday, 19 September 2023 at 03:44:18 UTC, Vitaliy Fadeev
wrote:
What D function or D operator does this?
```asm
IDIV EAX, r/m32
```
```
IDIV 5, 2
EAX = 2
EDX = 1
```
and returns (2,1) at once?
You can either use function `out` parameters with return value or
`tuples`:
```D
import std.typecons;
// with tuples
auto getVal(int a, int b) {
// ...
return tuple(integer, frac);
}
// out params
int getVal2(int a, int b, out int frac) {
// ...
frac = _fraq;
return integer;
}
// USAGE
{
// with tuples
auto v = getVal(5, 2);
assert(v[0] == 2);
assert(v[1] == 1);
// with out params
int frac;
int integer = getVal2(5, 2, frac);
assert(integer == 2);
assert(frac == 1);
}
```
Re: Which function returns a pair after division ? (integer,frac)
There are no operators for this, not that you need one.
```d
void func(int numerator, int denominator, out int quotient, out int
remainder) {
quotient = numerator / denominator;
remainder = numerator % denominator;
}
```
This will produce with ldc2 -O3:
```
void example.func(int, int, out int, out int):
mov r8, rdx
mov eax, edi
cdq
idivesi
mov dword ptr [r8], eax
mov dword ptr [rcx], edx
ret
```
Embrace modern backends, they are amazing!
Re: Which function returns a pair after division ? (integer,frac)
On Tuesday, 19 September 2023 at 03:53:06 UTC, Richard (Rikki)
Andrew Cattermole wrote:
There are no operators for this, not that you need one.
```d
void func(int numerator, int denominator, out int quotient, out
int remainder) {
quotient = numerator / denominator;
remainder = numerator % denominator;
}
```
This will produce with ldc2 -O3:
```
void example.func(int, int, out int, out int):
mov r8, rdx
mov eax, edi
cdq
idivesi
mov dword ptr [r8], eax
mov dword ptr [rcx], edx
ret
```
Embrace modern backends, they are amazing!
Thanks, Rikki. Optimization is good!
May be exist native D function or D-operator, like ```(a,b) = x
/% y;``` ?
Re: Detect 8-bit alligned type TXY by TX,TY.
I assume what you are wanting is to get the alignment for a given type? https://dlang.org/spec/property.html#alignof If instead you want the offset of a given field that's different. ``T.field.offsetof`` https://dlang.org/spec/struct.html#struct_field_properties Note: alignment cannot be represented by a type, it can only be represented by a number (for instance it could be 3).
Re: container vs standard array
On Tuesday, 19 September 2023 at 00:34:01 UTC, vino wrote:
Hi All,
I am trying to understand as to why the below code is throwing
error
Code
```
import std.stdio: writeln;
import std.container.array;
void main () {
//auto a = Array!string("Aname"); // throws error
auto b = Array!char("Bname");// works
auto c = Array!string("Aname", "Bname"); // works
//writeln(a);
writeln("Container Array :", b);
writeln("Container Array :", c);
writeln();
string[] d = ["Dname"]; // works
string[] e = ["Dname", "Ename"]; // works
writeln("Standard Array :", d);
writeln("Standard Array :", e);
}
```
From,
Vino
Looks to me like when it receives a single range it expects the
elements of that range to match the type. If I am correct in the
first one if you replace the "Aname" by ["Aname"] it should work
Re: Detect 8-bit alligned type TXY by TX,TY.
On Tuesday, 19 September 2023 at 06:33:25 UTC, Richard (Rikki)
Andrew Cattermole wrote:
I assume what you are wanting is to get the alignment for a
given type?
https://dlang.org/spec/property.html#alignof
If instead you want the offset of a given field that's
different.
``T.field.offsetof``
https://dlang.org/spec/struct.html#struct_field_properties
Note: alignment cannot be represented by a type, it can only be
represented by a number (for instance it could be 3).
Thank, Richard.
```.offsetof...``` mmm...
May be exists some like:
```d
// TXYXY = Detect!(TX,TX)
// Detect!(uint,uint) == ulong
template Detect(TX,TY)
{
static if ( TX.sizeof + TY.sizeof <= 8 )
alias Detect = ubyte;
else
static if ( TX.sizeof + TY.sizeof <= 16 )
alias Detect = ushort;
else
static if ( TX.sizeof + TY.sizeof <= 32 )
alias Detect= uint;
else
static if ( TX.sizeof + TY.sizeof <= 64 )
alias Detect= ulong;
else
static if ( TX.sizeof + TY.sizeof <= 128 )
alias Detect= ucent;
else
static assert( 0, "Expected size TX+TY <= 128" );
}
```
