force push! and unshift! need at least one item

Author: jakebolewski

base/abstractarray.jl

@@ -1453,10 +1453,8 @@ end
 
 # multi-item push!, unshift! (built on top of type-specific 1-item version)
 # (note: must not cause a dispatch loop when 1-item case is not defined)
-push!(A) = A
 push!(A, a, b) = push!(push!(A, a), b)
 push!(A, a, b, c...) = push!(push!(A, a, b), c...)
-unshift!(A) = A
 unshift!(A, a, b) = unshift!(unshift!(A, b), a)
 unshift!(A, a, b, c...) = unshift!(unshift!(A, c...), a, b)
 

doc/stdlib/collections.rst

@@ -800,7 +800,7 @@ Dequeues
 
 .. function:: push!(collection, items...) -> collection
 
-   Insert zero or more ``items`` at the end of ``collection``.
+   Insert one or more ``items`` at the end of ``collection``.
 
    .. doctest::
 
@@ -846,7 +846,7 @@ Dequeues
 
 .. function:: unshift!(collection, items...) -> collection
 
-   Insert zero or more ``items`` at the beginning of ``collection``.
+   Insert one or more ``items`` at the beginning of ``collection``.
 
    .. doctest::
 

test/arrayops.jl

@@ -832,6 +832,12 @@ A = [NaN]; B = [NaN]
 @test isequal(A,B)
 @test A!==B
 
+# test that single arugment push!, unshift! are not defined
+let A = []
+    @test_throws MethodError push!(a)
+    @test_throws MethodError unshift!(a)
+end
+
 # complete testsuite for reducedim
 
 # Inferred types