Can't use a parametric function in another function's parametric list

[dank-openai]

Describe the bug

Motivating example: I want to use apfloat::min_normal_exp<EXP_SZ>() to define a new apfloat:: min_subnormal_exp<...>. My new function wants to return the smallest bitwidth that fits the integer returned. So naturally I call apfloat::min_normal_exp from within the parameter list to compute the returned bitwidth. But that's not working.

To Reproduce

Try to compile this:

// Returns the unbiased exponent of the smallest subnormal number representable by an apfloat
// with the given number of exponent and fraction bits.
pub fn min_subnormal_exp
    <EXP_SZ: u32, FRACTION_SZ: u32,
     R:
     u32 = {
         std::clog2(
             (-(apfloat::min_normal_exp<EXP_SZ>() as s32 - FRACTION_SZ as s32 - s32:1)) as u32) +
         u32:1} > () -> sN[R] {
     (apfloat::min_normal_exp<EXP_SZ>() as s32 - FRACTION_SZ as s32) as sN[R]
}

#[test]
fn test_min_subnormal_exp() {
    assert_eq(
        min_subnormal_exp<u32:8, u32:23>(),
        s9:-149);
}

and observe error:

1754:      u32 = {
1755:          std::clog2(
1756:              (-(apfloat::min_normal_exp<EXP_SZ>() as s32 - FRACTION_SZ as s32 - s32:1)) as u32) +
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^----^ TypeInferenceError: uN[32] Parametric expression `EXP_SZ` was not constexpr -- parametric values must be compile-time constants
1757:          u32:1} > () -> sN[R] {

Expected behavior
It should work without type error.

[mikex-oss]

Are you sure it's because the called function is parametric? And not because it's imported? #1941 (comment)

[dank-openai]

I was importing apfloat::min_normal_exp so no, I'm not sure.
The error messages are different, FWIW.