Re: d strings are the bane of my existance
On Sunday, 5 December 2021 at 16:24:34 UTC, Chris Katko wrote:
I know there "is" a solution, it's just so odd to have this
much difficulty using a string.
Paying attention to the online docs would help you too ;-)
https://dlang.org/library/std/socket/internet_address.this.html
But, in the event you do 'need' to work with strings, you can
just convert the string to ushort.
// ---
module test;
import std.stdio : writeln;
import std.socket : InternetAddress;
import std.conv : to;
void main()
{
string host = "localhost";
string port = "8080";
auto ia = new InternetAddress(host, to!ushort(port));
writeln(ia);
}
//---
C++ bindings: const(T) dropped in return types of templates ?
I am trying to auto-generate bindings for C++ code in D. I've
come across something that looks like a bug in DMD to me, but
since I'm such a newbie in D maybe I am missing something.
My C++ class looks like this:
```cpp
template
struct Vec3Template
{
static const Vec3Template ZeroVector();
};
```
And my D binding code looks like this:
```cpp
extern(C++) struct Vec3Template(TYPE)
{
static const(Vec3Template!(TYPE)) ZeroVector();
}
alias Vec3 = Vec3Template!(float);
```
However, when I try to use Vec3.ZeroVector() I am getting a
linker error about unresolved symbols. It works with other
functions, the error is specific to this function.
Now it complains that it can't find this one:
`?ZeroVector@?$Vec3Template@M@@SA?AU1@XZ`
However, I am using castXml to extract my C++ information, and
that says that the mangled name should be:
`?ZeroVector@?$Vec3Template@M@@SA?BU1@XZ`
Running both names through undname.exe, an MSVC tool that
generates the undecorated function name from the mangled name, it
says that the latter function definition should be:
`public: static struct Vec3Template const __cdecl
Vec3Template::ZeroVector(void)`
Whereas the former definition would be:
`public: static struct Vec3Template __cdecl
Vec3Template::ZeroVector(void)`
So the one that D tries to link against is missing the `const`.
However, unless I misunderstood how to apply const to a type in
D, you can see that I did wrap the type in const(). (I also tried
immutable, but that's not allowed for extern C++ code).
So am I missing something, or did the compiler somehow forget
about the const-ness?
I'm currently using DMD64 D Compiler v2.098.0-dirty
Re: How to check for overflow when adding/multiplying numbers?
On Monday, 6 December 2021 at 18:38:37 UTC, Ola Fosheim Grøstad wrote: On Monday, 6 December 2021 at 17:46:35 UTC, Dave P. wrote: I’m porting some C code which uses the gcc intrinsics to do a multiply/add with overflow checking. See [here](https://gcc.gnu.org/onlinedocs/gcc/Integer-Overflow-Builtins.html) for reference. Is there a D equivalent? There is: https://dlang.org/phobos/core_checkedint.html I have never used it, so I don't know how well it performs. That seems to fit the bill. Thanks!
Re: How to check for overflow when adding/multiplying numbers?
On Monday, 6 December 2021 at 17:46:35 UTC, Dave P. wrote: I’m porting some C code which uses the gcc intrinsics to do a multiply/add with overflow checking. See [here](https://gcc.gnu.org/onlinedocs/gcc/Integer-Overflow-Builtins.html) for reference. Is there a D equivalent? There is: https://dlang.org/phobos/core_checkedint.html I have never used it, so I don't know how well it performs.
How to check for overflow when adding/multiplying numbers?
I’m porting some C code which uses the gcc intrinsics to do a multiply/add with overflow checking. See [here](https://gcc.gnu.org/onlinedocs/gcc/Integer-Overflow-Builtins.html) for reference. Is there a D equivalent?
Re: d strings are the bane of my existance
On 12/5/21 11:24 AM, Chris Katko wrote: All I want: ```d string ip_address = "192.168.1.1"; auto x = new InternetAddress( ip_string, "8008"); ``` ```d source/app.d(161,16): Error: none of the overloads of `this` are callable using argument types `(string, int)` `std.socket.InternetAddress.this(scope const(char)[] addr, ushort port)` ``` I know you have solved your problem, but take a look at the error message here -- "not callable using argument types `(string, int)`", whereas your sample has types `(string, string)`. It always helps to post *exactly* the code that is causing the problem, not code that you thought you used. If you want to make it simpler for posting, test the simpler code. I'm assuming to get that error you did something like: ```d auto port = 8008; auto x = new InternetAddress( ip_string, port); ``` This doesn't work, because port is inferred to be `int`, not `ushort`. You can fix by using `ushort` instead of `auto`, or using the literal right in the call. -Steve
Re: d strings are the bane of my existance
On Sunday, 5 December 2021 at 16:37:21 UTC, Chris Katko wrote: Yes! Thank you! I just realized the latter part was broken when I switched to using a uint for the addr. But I didn't know string is an alias for immutable(char)[]! Thank you! Yeah, a `const(char)[]` argument is designed to accept both `immutable(char)[]` (strings) and just `char[]` (mutable arrays of chars) for the arguments. Ivan Kazmenko.
