Fix unit test

src/reduce_dims.cpp

@@ -17,9 +17,7 @@ bool reduce_dim(std::vector<shape>& shapes, std::size_t n)
         auto blen    = s.lens()[n + 1];
 
         if(astride == bstride * blen or alen == 1)
-        {
             new_lens.push_back(alen * blen);
-        }
     }
     if(new_lens.size() != shapes.size())
         return false;
@@ -37,10 +35,25 @@ bool reduce_dim(std::vector<shape>& shapes, std::size_t n)
     return true;
 }
 
+void reduce_dim1(std::vector<shape>& shapes)
+{
+    if (std::any_of(shapes.begin(), shapes.end(), [&](const auto& s) {
+        return s.lens().back() != 1;
+    }))
+        return;
+    for(auto& s : shapes)
+    {
+        auto lens    = s.lens();
+        auto strides = s.strides();
+        lens.pop_back();
+        strides.pop_back();
+        s = shape{s.type(), lens, strides};
+    }
+}
+
 std::size_t reduce_dim_all(std::vector<shape>& shapes, std::size_t n)
 {
     while(reduce_dim(shapes, n) and n < shapes.size()) {}
-
     return n + 1;
 }
 void reduce_dim_all(std::vector<shape>& shapes)
@@ -48,6 +61,7 @@ void reduce_dim_all(std::vector<shape>& shapes)
     std::size_t n = 0;
     while(n < shapes.front().lens().size() - 1)
         n = reduce_dim_all(shapes, n);
+    reduce_dim1(shapes);
 }
 
 std::vector<std::size_t> base_lens(const std::vector<shape>& shapes)