replace function doesn't work on Tuples

[oschulz]

Just ran into this by chance: replace() seems broken for Tuples. It accepts a Tuple, but the generic implementation can't handle it:

julia> replace([1,2,3,4], 3 => 7)
4-element Array{Int64,1}:
 1
 2
 7
 4

julia> replace((1,2,3,4), 3 => 7)
ERROR: MethodError: no method matching similar(::NTuple{4,Int64}, ::Type{Int64})
[...]

Might be useful to add a specialized replace(::Tuple, ...) at some point (gen func for high performance?).

[ali-ramadhan]

Do we expect replace() to work for tuples?

Still an issue on

Julia Version 1.5.1
Commit 697e782ab8 (2020-08-25 20:08 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-9.0.1 (ORCJIT, skylake)

[ali-ramadhan]

Do we just need to define something like

_similar_or_copy(x::Tuple) = copy(x)

so that the following works?

julia/base/set.jl

Lines 555 to 564 in 8a52ea4

	function replace(A, old_new::Pair...; count::Union{Integer,Nothing}=nothing)
	V = promote_valuetype(old_new...)
	if count isa Nothing
	T = promote_type(subtract_singletontype(eltype(A), old_new...), V)
	replace_pairs!(_similar_or_copy(A, T), A, typemax(Int), old_new)
	else
	U = promote_type(eltype(A), V)
	replace_pairs!(_similar_or_copy(A, U), A, check_count(count), old_new)
	end
	end