diff --git a/docs/source/nnls_tutorial.rst b/docs/source/nnls_tutorial.rst
index 6546ee78a..acbb9a174 100644
--- a/docs/source/nnls_tutorial.rst
+++ b/docs/source/nnls_tutorial.rst
@@ -78,7 +78,7 @@ function :math:`f(x) = 10 - x`:
    struct CostFunctor {
       template <typename T>
       bool operator()(const T* const x, T* residual) const {
-        residual[0] = T(10.0) - x[0];
+        residual[0] = 10.0 - x[0];
         return true;
       }
    };
@@ -338,7 +338,7 @@ in the objective functor. Here is the code for evaluating
  struct F4 {
    template <typename T>
    bool operator()(const T* const x1, const T* const x4, T* residual) const {
-     residual[0] = T(sqrt(10.0)) * (x1[0] - x4[0]) * (x1[0] - x4[0]);
+     residual[0] = sqrt(10.0) * (x1[0] - x4[0]) * (x1[0] - x4[0]);
      return true;
    }
  };
@@ -471,7 +471,7 @@ residual. There will be a residual for each observation.
 
    template <typename T>
    bool operator()(const T* const m, const T* const c, T* residual) const {
-     residual[0] = T(y_) - exp(m[0] * T(x_) + c[0]);
+     residual[0] = y_ - exp(m[0] * x_ + c[0]);
      return true;
    }
 
@@ -653,7 +653,7 @@ The details of this camera model can be found the `Bundler homepage
      const T& l1 = camera[7];
      const T& l2 = camera[8];
      T r2 = xp*xp + yp*yp;
-     T distortion = T(1.0) + r2  * (l1 + l2  * r2);
+     T distortion = 1.0 + r2  * (l1 + l2  * r2);
 
      // Compute final projected point position.
      const T& focal = camera[6];