Usage of new keyword changes const-ness properties of variable

[Southclaws]

Is this a BUG REPORT, FEATURE REQUEST or QUESTION?:

• Bug Report
• Feature Request
• Question

What happened:

Using a new const cell as an array size:

new const MAX_OBJECT_ID_LEN = 25;
static PlayerObjectID[MAX_PLAYERS][MAX_OBJECT_ID_LEN];

Results in:

F:\Projects\samp-sandbox\gamemodes\sandbox\player-auth\player-auth.inc:26 (error) must be a constant expression; assumed zero
F:\Projects\samp-sandbox\gamemodes\sandbox\player-auth\player-auth.inc:26 (error) invalid array size (negative, zero or out of bounds)

What you expected to happen:

No error, since the value is const, I wouldn't expect the presence of new to change that fact.

How to reproduce it (as minimally and precisely as possible):

See above^

Anything else we need to know?:

Omitting new from the declaration compiles fine:

const MAX_OBJECT_ID_LEN = 25;
static PlayerObjectID[MAX_PLAYERS][MAX_OBJECT_ID_LEN];

[YashasSamaga]

const makes the symbol constant
new allocates memory for the symbol

Just using const makes the symbol a compile time constant whereas using new const allocates space for the symbol but makes it immutable.

Since you have used new, the symbol actually takes up space in the stack/data section. Hence, you can't get the value at compile time.

I haven't verified what's written above against what's given in the language guide but that's how the compiler works.

[Daniel-Cortez]

This one must be related: #70.

[Y-Less]

Just did a quick test, this compiles fine:

main()
{
	new a = 5;
	new const b = a;
	printf("%d", b);
}

So they aren't truly compile-time constants, just values that can't be changed after initial assignment.

[Y-Less]

const b = a; fails, as does b = 7;.

[Southclaws]

Seems I misunderstood the semantics of the keywords. Now it's clear, it makes total sense why there is a difference. I also didn't know new had more semantic meaning than just "create a variable" - allocation at run time explains this perfectly.

[Y-Less]

To be fair, this is another of those extreme corner cases most people don't know - I had to do an experiment then to work it out.