Missing element promotion in I(n)*F.Q'

[olof3]

Looking into some other problems with the Q in QR related to #38972, I noticed that a method is missing. Not a big deal, and pretty much any change to this example makes it work. But perhaps it is convenient to fix this at the same time as #38972.

I(n)*F.Q'
ERROR: MethodError: no method matching rmul!(::Matrix{Bool}, ::Adjoint{Float64, LinearAlgebra.QRCompactWYQ{Float64, Matrix{Float64}}})
Closest candidates are:

[ArunS-tack]

When i try to change the rmul! method to accommodate Matrix{Bool}, it gives me a gemqrt! error which is weird.

MethodError: no method matching gemqrt!(::Char, ::Char, ::Matrix{Float64}, ::Matrix{Float64}, ::Matrix{Bool})
Closest candidates are:
  gemqrt!(::AbstractChar, ::AbstractChar, ::AbstractMatrix{Float64}, ::AbstractMatrix{Float64}, !Matched::AbstractVecOrMat{Float64}) at /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/LinearAlgebra/src/lapack.jl:2903
  gemqrt!(::AbstractChar, ::AbstractChar, !Matched::AbstractMatrix{Float32}, !Matched::AbstractMatrix{Float32}, !Matched::AbstractVecOrMat{Float32}) at /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/LinearAlgebra/src/lapack.jl:2903
  gemqrt!(::AbstractChar, ::AbstractChar, !Matched::AbstractMatrix{ComplexF64}, !Matched::AbstractMatrix{ComplexF64}, !Matched::AbstractVecOrMat{ComplexF64}) at /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/LinearAlgebra/src/lapack.jl:2903
  ...
rmul!(A::Matrix{Bool}, adjB::Adjoint{Float64, LinearAlgebra.QRCompactWYQ{Float64, Matrix{Float64}}}) at untitled-215ef2cca844deeb6458ec9e9f956dfb:4
*(D::Diagonal{Bool, Vector{Bool}}, adjQ::Adjoint{Float64, LinearAlgebra.QRCompactWYQ{Float64, Matrix{Float64}}}) at diagonal.jl:270
top-level scope at untitled-215ef2cca844deeb6458ec9e9f956dfb:11
eval at boot.jl:360 [inlined]

Why is it not catching Char under AbstractChar?

[andreasnoack]

I've updated the title. The error is a bit misleading. We shouldn't have an rmul! method for Bool elements as there is no way that you can apply a reflection to a matrix of Booleans. Instead, the multiplication method should promote the elements to the element type of the Q matrix.