Fix reference constructors (#9)

Author: Tokazama

Project.toml

@@ -1,7 +1,7 @@
 name = "ManualMemory"
 uuid = "d125e4d3-2237-4719-b19c-fa641b8a4667"
 authors = ["chriselrod <[email protected]> and contributors"]
-version = "0.1.5"
+version = "0.1.6"
 
 [compat]
 julia = "1.5"

src/ManualMemory.jl

@@ -53,9 +53,10 @@ end
 mutable struct Reference{T}
     data::T
 
-    Reference{T}() where {T} = new()
-    Reference{T}(x) where {T} = new(x)
+    Reference{T}() where {T} = new{T}()
+    Reference(x) = new{typeof(x)}(x)
 end
+@inline Base.pointer(r::Reference{T}) where {T} = Ptr{T}(pointer_from_objref(r))
 @inline load(p::Ptr{Reference{T}}) where {T} = getfield(ccall(:jl_value_ptr, Ref{Reference{T}}, (Ptr{Cvoid},), unsafe_load(Base.unsafe_convert(Ptr{Ptr{Cvoid}}, p))), :data)
 @inline dereference(r::Reference) = getfield(r, :data)
 @inline dereference(x) = x

test/runtests.jl

@@ -1,4 +1,4 @@
-using ManualMemory: MemoryBuffer, load, store!, LazyPreserve, preserve, PseudoPtr
+using ManualMemory: MemoryBuffer, load, store!, LazyPreserve, preserve, PseudoPtr, Reference
 using Test
 
 @testset "ManualMemory.jl" begin
@@ -24,6 +24,13 @@ using Test
   p = 1 + p
   store!(p, 3)
   @test load(p) === 3
+
+  x = Reference{Int}()
+  y = Reference(1)
+  GC.@preserve x y begin
+    store!(pointer(x), 1)
+    @test load(pointer(x)) === 1 === load(pointer(y))
+  end
 end
 
 using ThreadingUtilities