Missing subscript error with templates

[steep bolt]

this constructor get's an error missing subscript:

BasicMatrix(T InMatrix[Size_Y][Size_X]) {
            _1_MatrixData = new T[Size_X * Size_Y]; 

            for (unsigned long long i = 0; i < Size_Y; i++) {
                for (unsigned long long j = 0; j < Size_X; j++) {
                    _1_MatrixData[i * Size_X + j] = InMatrix[i][j];
                }
            }


        }

Size_X and Size_Y are template arguments

template<size_t Size_X, size_t Size_Y, typename T, bool EnableIntrinsics = false>
    class BasicMatrix {

[hardy hinge]

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[raw cloak]

_1_MatrixData <- this is bad

some names beginning with underscores are reserved by the spec, so as a rule of thumb, don't do this, use a trailing _ if you wish instead, that's fine, like MatrixData_1_

but I don't see much of a reason to use leading nor trailing _ there, it's a member var, and your param name is already different, so there's no conflict

[steep bolt]

that's what the 1 is for. double _ also has that rule, but there is no rule for 1, and I highly doubt it'll be used in the standard, that's why I use it with my code

[raw cloak]

also, as written, this is a memory leak

[raw cloak]

I mean, you can rationalize it however you want, it's still bad practice, and un-necessary here

yes, it's true, that not all names beginning with underscore are forbidden, by why tempt fate?

[steep bolt]

it frees the memory in the destructor, I just sent the constructor

[raw cloak]

not enough information, send a minimal reproducible example

https://stackoverflow.com/help/minimal-reproducible-example

[steep bolt]

https://github.com/siladrenja/sandbox

The problem is in mymath.hpp

[raw cloak]

good, but neither minimal nor reproducible

also appears you are not in compliance with the https://en.cppreference.com/w/cpp/language/rule_of_three

[steep bolt]

it's literally the whole code, it's reproducible

[raw cloak]

no it's not

not in the sense that the SO guide suggests

it uses OpenGL etc, I have no idea how to build or if your build even works, I'm not going to bother

also it's not minimal, it does not include exactly and only the relevant details to demonstrate the problem, in a reproducible way, and nothing more

maybe someone else wants to try your build and wade through your full code, but I don't

[steep bolt]

mymath.hpp doesn't use opengl

[raw cloak]

it seems you're missing the point

[steep bolt]

most files are independent of eachother

[raw cloak]

but, you know, good luck, maybe someone else will help

[steep bolt]

and for minimal, I gave minimal example in the original question. IDK where the problem is so IDK how to reproduce it minimally

[raw cloak]

too minimal, and not reproducible

[raw cloak]

;compile

[versed matrix]

Compiler Output

<source>: In function 'int main()':
<source>:3:1: error: a template declaration cannot appear at block scope
    3 | template<size_t Size_X, size_t Size_Y, typename T, bool EnableIntrinsics = false>
      | ^~~~~~~~
<source>:7:2: error: expected '}' at end of input
    7 | }
      |  ^
<source>:2:16: note: to match this '{'
    2 | int main(void) {
      |                ^
Build failed

Bonkers#4468 | c++ | x86-64 gcc 12.2 | godbolt.org

[raw cloak]

if it was in line with the SO guide, I could do that ☝️

[steep bolt]

        template<size_t Size_X, size_t Size_Y, typename T, bool EnableIntrinsics = false>
    class BasicMatrix {
    public:
        BasicMatrix(T InMatrix[Size_Y][Size_X]) {
            _1_MatrixData = new T[Size_X * Size_Y]; 

            for (unsigned long long i = 0; i < Size_Y; i++) {
                for (unsigned long long j = 0; j < Size_X; j++) {
                    _1_MatrixData[i * Size_X + j] = InMatrix[i][j];
                }
            }


        }
                ~BasicMatrix() {
            delete _1_MatrixData;
        }
         }

[raw cloak]

but obviously that doesn't work for, you know, obvious reasons

[raw cloak]

;compile

[versed matrix]

Compiler Output

<source>: In function 'int main()':
<source>:3:1: error: a template declaration cannot appear at block scope
    3 | template<size_t Size_X, size_t Size_Y, typename T, bool EnableIntrinsics = false>
      | ^~~~~~~~
Build failed

Bonkers#4468 | c++ | x86-64 gcc 12.2 | godbolt.org

[raw cloak]

still nope

like yes, this probably requires that you expend effort to create a minimal reproducible example

if you are willing to spend that effort, I'm willing to help

[steep bolt]

as I said, since IDK what the problem is, how can I do that? I just managed to copy the whole class to a separate project and it works, so the problem is probably somewhere outside of the class, but it shouldn't be according to the error

[raw cloak]

well yes, that's what happens when you get more than a few lines of code

and that's why you create an MRE

[steep bolt]

ok, now there is really something weird, I deleted the whole main function to try and strip down the class and it worked

[raw cloak]

because, for example, by trying to create an MRE, you have discovered where the problem probably is not

[steep bolt]

and I just did ctrl+z until everything was back in place as it was before, and the error dissapeared

[raw cloak]

and half the time, creating an MRE, you will find your own problem and therefor you don't need our help

but then if you still need help, you have something that is reasonable to ask us to look at and help with

[steep bolt]

So nothing is changed, error is not there

[raw cloak]

indeed, if you cannot reproduce an error, it is difficult to diagnose

maybe you forgot to save a file? idk, I still do that sometimes

[steep bolt]

I didn't, and also VS does that automatically when I try to build

[raw cloak]

[steep bolt]

this is the prime example of a meme I saw a while a back. How we programmers have 2 moods. "it doesn't work, why?" and "it works... why?"

anyways, thx

!solved