# \#ambiguities

**URL:** https://discourse.julialang.org/tag/ambiguities/1438.md

[Latest](https://discourse.julialang.org/latest.md) · [Categories](https://discourse.julialang.org/categories.md) · [Tags](https://discourse.julialang.org/tags.md)

---

## [Method ambiguity involving diagonal types](https://discourse.julialang.org/t/method-ambiguity-involving-diagonal-types/133907)

<div class="topic-metadata">

**Author:** [@frankwswang](https://discourse.julialang.org/u/frankwswang)\
**Replies:** 10\
**Last updated:** [November 18, 2025, 8:53am UTC](https://discourse.julialang.org/t/method-ambiguity-involving-diagonal-types/133907 "2025-11-18T08:53:59Z")

</div>

MWE: julia\> f1(argL::T, argR::T) where {T} = 1 f1 (generic function with 1 method) julia\> f1(argL::T1, argR::T2) where {T, T1\<:AbstractArray{T}, T2\<:AbstractArray{T}} = 2 f1 (generic function with 2 methods) julia\> f1…

---

## [Could type ambiguity based on \`Union\` of concrete types be eliminated?](https://discourse.julialang.org/t/could-type-ambiguity-based-on-union-of-concrete-types-be-eliminated/126221)

<div class="topic-metadata">

**Author:** [@frankwswang](https://discourse.julialang.org/u/frankwswang)\
**Replies:** 4\
**Last updated:** [March 4, 2025, 6:03pm UTC](https://discourse.julialang.org/t/could-type-ambiguity-based-on-union-of-concrete-types-be-eliminated/126221 "2025-03-04T18:03:47Z")

</div>

MWE: julia\> foo(::Union{Int, Float64}, ::AbstractArray, ::AbstractArray) = 1 foo (generic function with 1 method) julia\> foo(::Int, ::Any, ::Any) = 2 foo (generic function with 2 methods) julia\> foo(1, \[1\], \[1\]) ERROR…

---

## [Resolving method ambiguity with Union](https://discourse.julialang.org/t/resolving-method-ambiguity-with-union/121106)

<div class="topic-metadata">

**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 8\
**Last updated:** [October 10, 2024, 9:09am UTC](https://discourse.julialang.org/t/resolving-method-ambiguity-with-union/121106 "2024-10-10T09:09:13Z")

</div>

Suppose I am trying to define a hvcat for a user type, and after I deal with the first argument (which can be an Int, or a Tuple{Vararg{Int}), the methods share a lot of code. So it would be ideal for me to just branch o…

---

## [Aqua.jl finds many ambiguities in Core, Base](https://discourse.julialang.org/t/aqua-jl-finds-many-ambiguities-in-core-base/103963)

<div class="topic-metadata">

**Author:** [@Joris\_Pinkse](https://discourse.julialang.org/u/Joris_Pinkse)\
**Replies:** 5\
**Last updated:** [September 18, 2023, 7:36pm UTC](https://discourse.julialang.org/t/aqua-jl-finds-many-ambiguities-in-core-base/103963 "2023-09-18T19:36:21Z")

</div>

I’m using Aqua.jl on my package and have addressed all issues that Aqua complained about except that it finds many ambiguities when I call Aqua.test\_all on my package, but none if I call Aqua.test\_ambiguities on my packa…