apply code review

base/abstractarray.jl

@@ -3400,9 +3400,9 @@ concatenate_setindex!(R, X::AbstractArray, I...) = (R[I...] = X)
 ## 1 argument
 
 function map!(f::F, dest::AbstractArray, A::AbstractArray) where F
-    for (i,j) in zip(eachindex(dest),eachindex(A))
-        val = f(@inbounds A[j])
-        @inbounds dest[i] = val
+    inds = LinearIndices(A)
+    for i = inds
+        dest[i] = f(A[i])
     end
     return dest
 end
@@ -3445,10 +3445,10 @@ map(f, ::AbstractSet) = error("map is not defined on sets")
 
 ## 2 argument
 function map!(f::F, dest::AbstractArray, A::AbstractArray, B::AbstractArray) where F
-    for (i, j, k) in zip(eachindex(dest), eachindex(A), eachindex(B))
-        @inbounds a, b = A[j], B[k]
-        val = f(a, b)
-        @inbounds dest[i] = val
+    inds = intersect(eachindex(LinearIndices(A)), eachindex(LinearIndices(B)))
+    @boundscheck checkbounds(dest, inds)
+    for i = inds
+        dest[i] = f(A[i], B[i])
     end
     return dest
 end
@@ -3462,15 +3462,10 @@ function ith_all(i, as)
 end
 
 function map_n!(f::F, dest::AbstractArray, As) where F
-    idxs1 = eachindex(LinearIndices(As[1]))
-    @boundscheck begin
-        idxs1 = intersect(map(eachindex ∘ LinearIndices, As)...)
-        checkbounds(dest, idxs1)
-    end
-    for i = idxs1
-        @inbounds I = ith_all(i, As)
-        val = f(I...)
-        @inbounds dest[i] = val
+    inds = mapreduce(eachindex ∘ LinearIndices, intersect, As)
+    @boundscheck checkbounds(dest, inds)
+    for i = inds
+        dest[i] = f(ith_all(i, As)...)
     end
     return dest
 end

test/abstractarray.jl

@@ -910,8 +910,25 @@ include("generic_map_tests.jl")
 generic_map_tests(map, map!)
 @test_throws ArgumentError map!(-, [1])
 
-# Issue #30624
-@test map!(+, [0,0,0], [1,2], [10,20,30], [100]) == [111,0,0]
+function test_30624()
+    ### unstructured
+    @test map!(+, ones(3), ones(3), ones(3), [1]) == [3, 1, 1]
+    @test map!(+, ones(3), [1], ones(3), ones(3)) == [3, 1, 1]
+    @test map!(+, [1], [1], [], []) == [1]
+    @test map!(+, [[1]], [1], [], []) == [[1]]
+
+    @test_throws BoundsError map!(+, ones(1), ones(2))
+    @test_throws BoundsError map!(+, ones(1), ones(2, 2))
+
+    @test map!(+, ones(3), view(ones(2, 3), 1:2, 2:3), ones(3)) == [2, 2, 2]
+    @test map!(+, ones(3), ones(2, 2), ones(3)) == [2, 2, 2]
+
+    ### structured (all mapped arguments are <:AbstractArray equal ndims > 1)
+    @test map!(+, ones(4), ones(2, 2), ones(2, 2)) == [2, 2, 2, 2]
+    @test map!(+, ones(4), ones(2, 2), ones(1, 2)) == [2, 2, 1, 1]
+    @test_throws BoundsError map!(+, ones(3), ones(2, 2), ones(2, 2))
+end
+test_30624()
 
 test_UInt_indexing(TestAbstractArray)
 test_13315(TestAbstractArray)