fix: deque push methods return the deque

Author: PraneethJain

src/StdLib/StdDeque.jl

@@ -4,8 +4,8 @@ Base.IndexStyle(::Type{<:StdDeque}) = IndexLinear()
 Base.size(v::StdDeque) = (Int(cppsize(v)),)
 Base.getindex(v::StdDeque, i::Int) = cxxgetindex(v, i)[]
 Base.setindex!(v::StdDeque{T}, val, i::Int) where {T} = cxxsetindex!(v, convert(T, val), i)
-Base.pushfirst!(v::StdDeque, x) = push_front!(v, x)
-Base.push!(v::StdDeque, x) = isempty(v) ? push_front!(v, x) : push_back!(v, x)
+Base.pushfirst!(v::StdDeque, x) = (push_front!(v, x); v)
+Base.push!(v::StdDeque, x) = (isempty(v) ? push_front!(v, x) : push_back!(v, x); v)
 Base.pop!(v::StdDeque) = pop_back!(v)
 Base.popfirst!(v::StdDeque) = pop_front!(v)
 Base.resize!(v::StdDeque, n::Integer) = resize!(v, n)

test/stdlib.jl

@@ -307,7 +307,7 @@ let
   deque1 = StdDeque{Int64}()
   @test length(deque1) == 0
   push!(deque1, 7)
-  push!(deque1, 9)
+  deque1 = push!(deque1, 9)
   @test length(deque1) == 2
   for (i, x) in enumerate(deque1)
     if i == 1