Slice assign value (#111)

* Assign value to slice

* Readme for formatting

README.md

@@ -40,6 +40,16 @@ cmake  -DTESTING=ON ..
 make check
 ```
 
+## Formatting
+The format can be checked as following:
+```
+mkdir build
+cd build
+cmake  -DFORMAT=ON ..
+make check_format
+```
+
+
 ## Example
 
 See the test directory for detailed examples. Some simple examples are included below:

matrix/Slice.hpp

@@ -63,6 +63,17 @@ public:
         return self;
     }
 
+    Slice<Type, P, Q, M, N>& operator=(const Type& other)
+    {
+        Slice<Type, P, Q, M, N>& self = *this;
+        for (size_t i = 0; i < P; i++) {
+            for (size_t j = 0; j < Q; j++) {
+                self(i, j) = other;
+            }
+        }
+        return self;
+    }
+
     // allow assigning vectors to a slice that are in the axis
     template <size_t DUMMY = 1> // make this a template function since it only exists for some instantiations
     Slice<Type, 1, Q, M, N>& operator=(const Vector<Type, Q>& other)

test/slice.cpp

@@ -125,6 +125,18 @@ int main()
     TEST(!v5.xy().longerThan(5.f));
     TEST(isEqualF(5.f, v5.xy().norm()));
 
+    // assign scalar value to slice
+    Matrix<float, 3, 1> L;
+    L(0,0) = -1;
+    L(1,0) = 1;
+    L(2,0) = 3;
+
+    L.slice<2,1>(0,0) = 0.0f;
+
+    float data_5_check[3] = {0, 0, 3};
+    Matrix<float, 3, 1> M (data_5_check);
+    TEST(isEqual(L, M));
+
     return 0;
 }