cgen error on init fixed size array of generic type

[larpon]

V version: V 0.4.9 2a69b7c, press to see full `v doctor` output

V full version	V 0.4.9 f048bb3.2a69b7c
OS	linux, "EndeavourOS Linux"
Processor	16 cpus, 64bit, little endian, AMD Ryzen 7 8845HS w/ Radeon 780M Graphics
Memory	19.6GB/30.64GB
V executable	/home/lmp/Projects/v/v
V last modified time	2025-01-21 08:39:50
V home dir	OK, value: /home/lmp/Projects/v
VMODULES	OK, value: /home/lmp/.vmodules
VTMP	OK, value: /dev/shm
Current working dir	OK, value: /home/lmp/Projects/v
Git version	git version 2.48.1
V git status	weekly.2025.03-19-g2a69b7c5 (2 commit(s) behind V master)
.git/config present	true
cc version	cc (GCC) 14.2.1 20240910
gcc version	gcc (GCC) 14.2.1 20240910
clang version	clang version 19.1.7
tcc version	tcc version 0.9.28rc 2024-07-31 HEAD@1cee0908 (x86_64 Linux)
tcc git status	thirdparty-linux-amd64 0134e9b9
emcc version	emcc (Emscripten gcc/clang-like replacement + linker emulating GNU ld) 3.1.72-git (437140d149d9c977ffc8b09dbaf9b0f5a02db190)
glibc version	ldd (GNU libc) 2.40

What did you do?
./v -g -o vdbg cmd/v && ./vdbg t.v && t

module main

import math.vec

pub struct Bezier {
pub mut:
	points [4]vec.Vec2[f32]
}

pub fn (b Bezier) h3() vec.Vec2[f32] {
	return b.points[2]
}

pub fn (b Bezier) h4() vec.Vec2[f32] {
	return b.points[3]
}

pub fn (b Bezier) end() vec.Vec2[f32] {
	return b.h4()
}

pub struct Path {
pub mut:
	segments [1024]Bezier
	len      int // should be read-only
}

pub fn (mut p Path) add(b Bezier) {
	assert p.len + 1 < 1024
	p.segments[p.len] = b
	p.len++
}

fn main() {
	b1 := Bezier{
		points: [vec.Vec2[f32]{100, 100}, vec.Vec2[f32]{120, 80},
			vec.Vec2[f32]{200, 70}, vec.Vec2[f32]{400, 200}]!
	}
	b2 := Bezier{
		points: [b1.end(), b1.h3() + vec.Vec2[f32]{0, 2 * 80}, vec.Vec2[f32]{200, 70},
			b1.end() + vec.Vec2[f32]{400, 200}]!
	}

	mut path := Path{}

	path.add(b1)
	path.add(b2)

	println(sizeof(path))
}

What did you see?

================== C compilation error (from tcc): ==============
cc: /dev/shm/t.01JJ4PA9HFFVSK3Y4YDY0MWBMP.tmp.c:7745: error: cannot convert 'struct math__vec__Vec2_T_f32' to 'void *'
=================================================================
(You can pass `-cg`, or `-show-c-output` as well, to print all the C error messages).
builder error: 
==================
C error found. It should never happen, when compiling pure V code.
This is a V compiler bug, please report it using `v bug file.v`,
or goto https://github.com/vlang/v/issues/new/choose .
You can also use #help on Discord: https://discord.gg/vlang .

What did you expect to see?

Something like "32772"

Workaround

module main

import math.vec

pub struct Bezier {
pub mut:
	points [4]vec.Vec2[f32]
}

pub fn (b Bezier) h3() vec.Vec2[f32] {
	return b.points[2]
}

pub fn (b Bezier) h4() vec.Vec2[f32] {
	return b.points[3]
}

pub fn (b Bezier) end() vec.Vec2[f32] {
	return b.h4()
}

pub struct Path {
pub mut:
	segments [1024]Bezier
	len      int // should be read-only
}

pub fn (mut p Path) add(b Bezier) {
	assert p.len + 1 < 1024
	p.segments[p.len] = b
	p.len++
}

fn main() {

	p_b1 := [vec.Vec2[f32]{100, 100}, vec.Vec2[f32]{120, 80}, vec.Vec2[f32]{200, 70}, vec.Vec2[f32]{400, 200}]!
	b1 := Bezier{
		points: p_b1
	}
	p_b2 := [b1.end(), b1.h3() + vec.Vec2[f32]{0, 2 * 80}, vec.Vec2[f32]{200, 70}, b1.end() + vec.Vec2[f32]{400, 200}]!
	b2 := Bezier{
		points: p_b2
	}

	mut path := Path{}

	path.add(b1)
	path.add(b2)

	println(sizeof(path))
}

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[huly-for-github]

Connected to Huly®: V_0.6-21973

[jorgeluismireles]

Another workaround, seems just b2 those extra operations are causing the problem:

	a := b1.end()
	b := b1.h3() + vec.Vec2[f32]{0, 2 * 80}
	c := vec.Vec2[f32]{200, 70}
	d := b1.end() + vec.Vec2[f32]{400, 200}
	b2 := Bezier{
		points: [a, b, c, d]!
	}

[jorgeluismireles]

But more likely because using b1 methods, this also works:

	a := b1.end()
	b := b1.h3() + vec.Vec2[f32]{0, 2 * 80}
	d := b1.end() + vec.Vec2[f32]{400, 200}
	b2 := Bezier{
		points: [a, b, vec.Vec2[f32]{200, 70}, d]!
	}