From 51d532342a6f2b30832edd6b68f6cfb8340905a8 Mon Sep 17 00:00:00 2001
From: Roger-luo <hiroger@qq.com>
Date: Wed, 24 Apr 2019 21:33:08 +0800
Subject: [PATCH] fix https://github.com/QuantumBFS/YaoBlocks.jl/issues/21

---
 src/register.jl  | 2 +-
 test/register.jl | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/register.jl b/src/register.jl
index 87df1b6..84905c6 100644
--- a/src/register.jl
+++ b/src/register.jl
@@ -114,7 +114,7 @@ ArrayReg(r::ArrayReg{B}) where B = ArrayReg{B}(copy(r.state))
 Base.copy(r::ArrayReg) = ArrayReg(r)
 Base.similar(r::ArrayRegOrAdjointArrayReg{B}) where B = ArrayReg{B}(similar(state(r)))
 
-function Base.copyto!(dst::R, src::R) where {R <: ArrayRegOrAdjointArrayReg}
+function Base.copyto!(dst::ArrayRegOrAdjointArrayReg, src::ArrayRegOrAdjointArrayReg)
     copyto!(state(dst), state(src))
     return dst
 end
diff --git a/test/register.jl b/test/register.jl
index a2cb843..8f87ffa 100644
--- a/test/register.jl
+++ b/test/register.jl
@@ -116,3 +116,11 @@ end
     focus!(r, 2:4)
     @test sum(r.state, dims=2) ≈ ArrayReg(bit"011").state
 end
+
+@testset "YaoBlocks.jl/issues/21" begin
+    st = rand(ComplexF64, 16, 2)
+    r1 = ArrayReg(view(st, :, 1))
+    r2 = ArrayReg(rand(ComplexF64, 16, 1))
+    copyto!(r1, r2)
+    @test r1 == r2
+end