prompt: You will be provided with a partial code base and an issue statement explaining a problem to resolve.
  <issue>
  [WIP] Fix assigning from complex to float (only test)
  When a user assign complex value to float array, it causes an error.
  
  </issue>
  <code>
  [start of cupy/core/_ufuncs.py]
  1 from cupy.core._kernel import create_ufunc
  2 
  3 elementwise_copy = create_ufunc(
  4     'cupy_copy',
  5     ('?->?', 'b->b', 'B->B', 'h->h', 'H->H', 'i->i', 'I->I', 'l->l', 'L->L',
  6      'q->q', 'Q->Q', 'e->e', 'f->f', 'd->d', 'F->F', 'D->D'),
  7     'out0 = out0_type(in0)', default_casting='unsafe')
  8 # complex numbers requires out0 = complex<T>(in0)
  9
  [end of cupy/core/_ufuncs.py]
  </code>
  
  I need you to solve this issue by generating a single patch file that I can apply directly to this repository using git apply. Please respond with a single patch file in the following format.
  <patch>
  diff --git a/file.py b/file.py
  --- a/file.py
  +++ b/file.py
  @@ -1,27 +1,35 @@
   def euclidean(a, b):
  -    while b:
  -        a, b = b, a % b
  -    return a
  +    if b == 0:
  +        return a
  +    return euclidean(b, a % b)
   
   
   def bresenham(x0, y0, x1, y1):
       points = []
       dx = abs(x1 - x0)
       dy = abs(y1 - y0)
  -    sx = 1 if x0 < x1 else -1
  -    sy = 1 if y0 < y1 else -1
  -    err = dx - dy
  +    x, y = x0, y0
  +    sx = -1 if x0 > x1 else 1
  +    sy = -1 if y0 > y1 else 1
   
  -    while True:
  -        points.append((x0, y0))
  -        if x0 == x1 and y0 == y1:
  -            break
  -        e2 = 2 * err
  -        if e2 > -dy:
  -            err -= dy
  -            x0 += sx
  -        if e2 < dx:
  -            err += dx
  -            y0 += sy
  +    if dx > dy:
  +        err = dx / 2.0
  +        while x != x1:
  +            points.append((x, y))
  +            err -= dy
  +            if err < 0:
  +                y += sy
  +                err += dx
  +            x += sx
  +    else:
  +        err = dy / 2.0
  +        while y != y1:
  +            points.append((x, y))
  +            err -= dx
  +            if err < 0:
  +                x += sx
  +                err += dy
  +            y += sy
  +
  +    points.append((x, y))
       return points
  
  </patch>
golden_diff: diff --git a/cupy/core/_ufuncs.py b/cupy/core/_ufuncs.py
  --- a/cupy/core/_ufuncs.py
  +++ b/cupy/core/_ufuncs.py
  @@ -1,8 +1,30 @@
   from cupy.core._kernel import create_ufunc
   
  +
  +_complex_cast_copy = '''
  +template<typename T, typename U>
  +__device__ void cast_copy(const U& x, T& y) {y = T(x);}
  +template<typename T, typename U>
  +__device__ void cast_copy(const complex<U>& x, complex<T>& y) {
  +    y = complex<T>(x);
  +}
  +template<typename T, typename U>
  +__device__ void cast_copy(const complex<U>& x, T& y) {y = T(x.real());}
  +'''
  +
  +
   elementwise_copy = create_ufunc(
       'cupy_copy',
       ('?->?', 'b->b', 'B->B', 'h->h', 'H->H', 'i->i', 'I->I', 'l->l', 'L->L',
        'q->q', 'Q->Q', 'e->e', 'f->f', 'd->d', 'F->F', 'D->D'),
  -    'out0 = out0_type(in0)', default_casting='unsafe')
  +    'cast_copy(in0, out0)',
  +    preamble=_complex_cast_copy, default_casting='unsafe')
  +
  +
  +elementwise_copy_where = create_ufunc(
  +    'cupy_copy_where',
  +    ('??->?', 'b?->b', 'B?->B', 'h?->h', 'H?->H', 'i?->i', 'I?->I', 'l?->l',
  +     'L?->L', 'q?->q', 'Q?->Q', 'e?->e', 'f?->f', 'd?->d', 'F?->F', 'D?->D'),
  +    'if (in1) cast_copy(in0, out0)',
  +    preamble=_complex_cast_copy, default_casting='unsafe')
   # complex numbers requires out0 = complex<T>(in0)
  
verification_info: {"golden_diff": "diff --git a/cupy/core/_ufuncs.py b/cupy/core/_ufuncs.py\n--- a/cupy/core/_ufuncs.py\n+++ b/cupy/core/_ufuncs.py\n@@ -1,8 +1,30 @@\n from cupy.core._kernel import create_ufunc\n \n+\n+_complex_cast_copy = '''\n+template<typename T, typename U>\n+__device__ void cast_copy(const U& x, T& y) {y = T(x);}\n+template<typename T, typename U>\n+__device__ void cast_copy(const complex<U>& x, complex<T>& y) {\n+    y = complex<T>(x);\n+}\n+template<typename T, typename U>\n+__device__ void cast_copy(const complex<U>& x, T& y) {y = T(x.real());}\n+'''\n+\n+\n elementwise_copy = create_ufunc(\n     'cupy_copy',\n     ('?->?', 'b->b', 'B->B', 'h->h', 'H->H', 'i->i', 'I->I', 'l->l', 'L->L',\n      'q->q', 'Q->Q', 'e->e', 'f->f', 'd->d', 'F->F', 'D->D'),\n-    'out0 = out0_type(in0)', default_casting='unsafe')\n+    'cast_copy(in0, out0)',\n+    preamble=_complex_cast_copy, default_casting='unsafe')\n+\n+\n+elementwise_copy_where = create_ufunc(\n+    'cupy_copy_where',\n+    ('??->?', 'b?->b', 'B?->B', 'h?->h', 'H?->H', 'i?->i', 'I?->I', 'l?->l',\n+     'L?->L', 'q?->q', 'Q?->Q', 'e?->e', 'f?->f', 'd?->d', 'F?->F', 'D?->D'),\n+    'if (in1) cast_copy(in0, out0)',\n+    preamble=_complex_cast_copy, default_casting='unsafe')\n # complex numbers requires out0 = complex<T>(in0)\n", "issue": "[WIP] Fix assigning from complex to float (only test)\nWhen a user assign complex value to float array, it causes an error.\n", "before_files": [{"content": "from cupy.core._kernel import create_ufunc\n\nelementwise_copy = create_ufunc(\n    'cupy_copy',\n    ('?->?', 'b->b', 'B->B', 'h->h', 'H->H', 'i->i', 'I->I', 'l->l', 'L->L',\n     'q->q', 'Q->Q', 'e->e', 'f->f', 'd->d', 'F->F', 'D->D'),\n    'out0 = out0_type(in0)', default_casting='unsafe')\n# complex numbers requires out0 = complex<T>(in0)\n", "path": "cupy/core/_ufuncs.py"}]}