diff --git a/docs/source/nnls_modeling.rst b/docs/source/nnls_modeling.rst
index 972ea5b..3b1cc28 100644
--- a/docs/source/nnls_modeling.rst
+++ b/docs/source/nnls_modeling.rst
@@ -223,7 +223,7 @@
 
       template <typename T>
       bool operator()(const T* const x , const T* const y, T* e) const {
-        e[0] = T(k_) - x[0] * y[0] - x[1] * y[1];
+        e[0] = k_ - x[0] * y[0] - x[1] * y[1];
         return true;
       }
 
@@ -281,12 +281,6 @@
    independent variables, and there is no limit on the dimensionality
    of each of them.
 
-   **WARNING 1** Since the functor will get instantiated with
-   different types for ``T``, you must convert from other numeric
-   types to ``T`` before mixing computations with other variables
-   of type ``T``. In the example above, this is seen where instead of
-   using ``k_`` directly, ``k_`` is wrapped with ``T(k_)``.
-
    **WARNING 2** A common beginner's error when first using
    :class:`AutoDiffCostFunction` is to get the sizing wrong. In particular,
    there is a tendency to set the template parameters to (dimension of
@@ -1420,7 +1414,7 @@
               delta[0] * delta[0] + delta[1] * delta[1] + delta[2] * delta[2];
 
           T q_delta[4];
-          if (squared_norm_delta > T(0.0)) {
+          if (squared_norm_delta > 0.0) {
             T norm_delta = sqrt(squared_norm_delta);
             const T sin_delta_by_delta = sin(norm_delta) / norm_delta;
             q_delta[0] = cos(norm_delta);
@@ -1454,12 +1448,6 @@
                                 Global Size ---------------+  |
                                 Local Size -------------------+
 
-  **WARNING:** Since the functor will get instantiated with different
-  types for ``T``, you must to convert from other numeric types to
-  ``T`` before mixing computations with other variables of type
-  ``T``. In the example above, this is seen where instead of using
-  ``k_`` directly, ``k_`` is wrapped with ``T(k_)``.
-
 
 :class:`Problem`
 ================
diff --git a/examples/curve_fitting.cc b/examples/curve_fitting.cc
index 210411e..3f577f8 100644
--- a/examples/curve_fitting.cc
+++ b/examples/curve_fitting.cc
@@ -125,7 +125,7 @@
   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;
   }
 
diff --git a/examples/ellipse_approximation.cc b/examples/ellipse_approximation.cc
index 1cd2379..7b2bf12 100644
--- a/examples/ellipse_approximation.cc
+++ b/examples/ellipse_approximation.cc
@@ -342,8 +342,8 @@
 
   template <typename T>
   bool operator()(const T* x0, const T* x1, T* residuals) const {
-    residuals[0] = T(sqrt_weight_) * (x0[0] - x1[0]);
-    residuals[1] = T(sqrt_weight_) * (x0[1] - x1[1]);
+    residuals[0] = sqrt_weight_ * (x0[0] - x1[0]);
+    residuals[1] = sqrt_weight_ * (x0[1] - x1[1]);
     return true;
   }
 
diff --git a/examples/helloworld.cc b/examples/helloworld.cc
index 4173b37..22dff55 100644
--- a/examples/helloworld.cc
+++ b/examples/helloworld.cc
@@ -48,7 +48,7 @@
 // derivatives.
 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;
   }
 };
diff --git a/examples/libmv_bundle_adjuster.cc b/examples/libmv_bundle_adjuster.cc
index 0c6c0d6..47d0cd7 100644
--- a/examples/libmv_bundle_adjuster.cc
+++ b/examples/libmv_bundle_adjuster.cc
@@ -471,9 +471,9 @@
   T r2 = x*x + y*y;
   T r4 = r2 * r2;
   T r6 = r4 * r2;
-  T r_coeff = (T(1) + k1*r2 + k2*r4 + k3*r6);
-  T xd = x * r_coeff + T(2)*p1*x*y + p2*(r2 + T(2)*x*x);
-  T yd = y * r_coeff + T(2)*p2*x*y + p1*(r2 + T(2)*y*y);
+  T r_coeff = 1.0 + k1 * r2 + k2 * r4 + k3 * r6;
+  T xd = x * r_coeff + 2.0 * p1 * x * y + p2 * (r2 + 2.0 * x * x);
+  T yd = y * r_coeff + 2.0 * p2 * x * y + p1 * (r2 + 2.0 * y * y);
 
   // Apply focal length and principal point to get the final image coordinates.
   *image_x = focal_length_x * xd + principal_point_x;
@@ -533,8 +533,8 @@
                                           &predicted_y);
 
     // The error is the difference between the predicted and observed position.
-    residuals[0] = predicted_x - T(observed_x);
-    residuals[1] = predicted_y - T(observed_y);
+    residuals[0] = predicted_x - observed_x;
+    residuals[1] = predicted_y - observed_y;
 
     return true;
   }
diff --git a/examples/more_garbow_hillstrom.cc b/examples/more_garbow_hillstrom.cc
index 835cb7f..5ba6d94 100644
--- a/examples/more_garbow_hillstrom.cc
+++ b/examples/more_garbow_hillstrom.cc
@@ -127,8 +127,8 @@
 BEGIN_MGH_PROBLEM(TestProblem1, 2, 2)
   const T x1 = x[0];
   const T x2 = x[1];
-  residual[0] = T(10.0) * (x2 - x1 * x1);
-  residual[1] = T(1.0) - x1;
+  residual[0] = 10.0 * (x2 - x1 * x1);
+  residual[1] = 1.0 - x1;
 END_MGH_PROBLEM;
 
 const double TestProblem1::initial_x[] = {-1.2, 1.0};
@@ -142,8 +142,8 @@
 BEGIN_MGH_PROBLEM(TestProblem2, 2, 2)
   const T x1 = x[0];
   const T x2 = x[1];
-  residual[0] = T(-13.0) + x1 + ((T(5.0) - x2) * x2 - T(2.0)) * x2;
-  residual[1] = T(-29.0) + x1 + ((x2 + T(1.0)) * x2 - T(14.0)) * x2;
+  residual[0] = -13.0 + x1 + ((5.0 - x2) * x2 - 2.0) * x2;
+  residual[1] = -29.0 + x1 + ((x2 + 1.0) * x2 - 14.0) * x2;
 END_MGH_PROBLEM;
 
 const double TestProblem2::initial_x[] = {0.5, -2.0};
@@ -157,8 +157,8 @@
 BEGIN_MGH_PROBLEM(TestProblem3, 2, 2)
   const T x1 = x[0];
   const T x2 = x[1];
-  residual[0] = T(10000.0) * x1 * x2 - T(1.0);
-  residual[1] = exp(-x1) + exp(-x2) - T(1.0001);
+  residual[0] = 10000.0 * x1 * x2 - 1.0;
+  residual[1] = exp(-x1) + exp(-x2) - 1.0001;
 END_MGH_PROBLEM;
 
 const double TestProblem3::initial_x[] = {0.0, 1.0};
@@ -171,9 +171,9 @@
 BEGIN_MGH_PROBLEM(TestProblem4, 2, 3)
   const T x1 = x[0];
   const T x2 = x[1];
-  residual[0] = x1  - T(1000000.0);
-  residual[1] = x2 - T(0.000002);
-  residual[2] = x1 * x2 - T(2.0);
+  residual[0] = x1  - 1000000.0;
+  residual[1] = x2 - 0.000002;
+  residual[2] = x1 * x2 - 2.0;
 END_MGH_PROBLEM;
 
 const double TestProblem4::initial_x[] = {1.0, 1.0};
@@ -186,9 +186,9 @@
 BEGIN_MGH_PROBLEM(TestProblem5, 2, 3)
   const T x1 = x[0];
   const T x2 = x[1];
-  residual[0] = T(1.5) - x1 * (T(1.0) - x2);
-  residual[1] = T(2.25) - x1 * (T(1.0) - x2 * x2);
-  residual[2] = T(2.625) - x1 * (T(1.0) - x2 * x2 * x2);
+  residual[0] = 1.5 - x1 * (1.0 - x2);
+  residual[1] = 2.25 - x1 * (1.0 - x2 * x2);
+  residual[2] = 2.625 - x1 * (1.0 - x2 * x2 * x2);
 END_MGH_PROBLEM;
 
 const double TestProblem5::initial_x[] = {1.0, 1.0};
@@ -202,9 +202,9 @@
   const T x1 = x[0];
   const T x2 = x[1];
   for (int i = 1; i <= 10; ++i) {
-    residual[i - 1] = T(2.0) + T(2.0 * i) -
-        (exp(T(static_cast<double>(i)) * x1) +
-         exp(T(static_cast<double>(i) * x2)));
+    residual[i - 1] = 2.0 + 2.0 * i -
+        (exp(static_cast<double>(i) * x1) +
+         exp(static_cast<double>(i) * x2));
   }
 END_MGH_PROBLEM;
 
@@ -220,9 +220,9 @@
   const T x1 = x[0];
   const T x2 = x[1];
   const T x3 = x[2];
-  const T theta = T(0.5 / M_PI)  * atan(x2 / x1) + (x1 > 0.0 ? T(0.0) : T(0.5));
-  residual[0] = T(10.0) * (x3 - T(10.0) * theta);
-  residual[1] = T(10.0) * (sqrt(x1 * x1 + x2 * x2) - T(1.0));
+  const T theta = (0.5 / M_PI)  * atan(x2 / x1) + (x1 > 0.0 ? 0.0 : 0.5);
+  residual[0] = 10.0 * (x3 - 10.0 * theta);
+  residual[1] = 10.0 * (sqrt(x1 * x1 + x2 * x2) - 1.0);
   residual[2] = x3;
 END_MGH_PROBLEM;
 
@@ -243,10 +243,10 @@
                 0.73, 0.96, 1.34, 2.10, 4.39};
 
   for (int i = 1; i <=15; ++i) {
-    const T u = T(static_cast<double>(i));
-    const T v = T(static_cast<double>(16 - i));
-    const T w = T(static_cast<double>(std::min(i, 16 - i)));
-    residual[i - 1] = T(y[i - 1]) - (x1 + u / (v * x2 + w * x3));
+    const double u = static_cast<double>(i);
+    const double v = static_cast<double>(16 - i);
+    const double w = static_cast<double>(std::min(i, 16 - i));
+    residual[i - 1] = y[i - 1] - (x1 + u / (v * x2 + w * x3));
   }
 END_MGH_PROBLEM;
 
@@ -269,9 +269,8 @@
                       0.3989,
                       0.3521, 0.2420, 0.1295, 0.0540, 0.0175, 0.0044, 0.0009};
   for (int i = 0; i < 15; ++i) {
-    const T t_i = T((8.0 - i - 1.0) / 2.0);
-    const T y_i = T(y[i]);
-    residual[i] = x1 * exp(-x2 * (t_i - x3) * (t_i - x3) / T(2.0)) - y_i;
+    const double t_i = (8.0 - i - 1.0) / 2.0;
+    residual[i] = x1 * exp(-x2 * (t_i - x3) * (t_i - x3) / 2.0) - y[i];
   }
 END_MGH_PROBLEM;
 
@@ -291,9 +290,8 @@
                       8261, 7030, 6005, 5147, 4427, 3820, 3307, 2872};
 
   for (int i = 0; i < 16; ++i) {
-    const T ti = T(45 + 5.0 * (i + 1));
-    const T yi = T(y[i]);
-    residual[i] = x1 * exp(x2 / (ti + x3)) - yi;
+    const double ti = 45.0 + 5.0 * (i + 1);
+    residual[i] = x1 * exp(x2 / (ti + x3)) - y[i];
   }
 END_MGH_PROBLEM
 
@@ -314,7 +312,7 @@
   for (int i = 1; i <= 100; ++i) {
     const double ti = static_cast<double>(i) / 100.0;
     const double yi = 25.0 + pow(-50.0 * log(ti), 2.0 / 3.0);
-    residual[i - 1] = exp(-pow(abs(T(yi * 100.0 * i) * x2), x3) / x1) - T(ti);
+    residual[i - 1] = exp(-pow(abs((yi * 100.0 * i) * x2), x3) / x1) - ti;
   }
 END_MGH_PROBLEM
 
@@ -330,13 +328,13 @@
   const T x2 = x[1];
   const T x3 = x[2];
 
-  const T t1 = T(0.1);
-  const T t2 = T(0.2);
-  const T t3 = T(0.3);
+  const double t1 = 0.1;
+  const double t2 = 0.2;
+  const double t3 = 0.3;
 
-  residual[0] = exp(-t1 * x1) - exp(-t1 * x2) - x3 * (exp(-t1) - exp(-T(10.0) * t1));
-  residual[1] = exp(-t2 * x1) - exp(-t2 * x2) - x3 * (exp(-t2) - exp(-T(10.0) * t2));
-  residual[2] = exp(-t3 * x1) - exp(-t3 * x2) - x3 * (exp(-t3) - exp(-T(10.0) * t3));
+  residual[0] = exp(-t1 * x1) - exp(-t1 * x2) - x3 * (exp(-t1) - exp(-10.0 * t1));
+  residual[1] = exp(-t2 * x1) - exp(-t2 * x2) - x3 * (exp(-t2) - exp(-10.0 * t2));
+  residual[2] = exp(-t3 * x1) - exp(-t3 * x2) - x3 * (exp(-t3) - exp(-10.0 * t3));
 END_MGH_PROBLEM
 
 const double TestProblem12::initial_x[] = {0.0, 10.0, 20.0};
@@ -352,9 +350,9 @@
   const T x3 = x[2];
   const T x4 = x[3];
 
-  residual[0] = x1 + T(10.0) * x2;
-  residual[1] = T(sqrt(5.0)) * (x3 - x4);
-  residual[2] = (x2 - T(2.0) * x3) * (x2 - T(2.0) * x3);
+  residual[0] = x1 + 10.0 * x2;
+  residual[1] = sqrt(5.0) * (x3 - x4);
+  residual[2] = (x2 - 2.0 * x3) * (x2 - 2.0 * x3);
   residual[3] = sqrt(10.0) * (x1 - x4) * (x1 - x4);
 END_MGH_PROBLEM
 
@@ -374,22 +372,22 @@
   const T x3 = x[2];
   const T x4 = x[3];
 
-  residual[0] = T(10.0) * (x2 - x1 * x1);
-  residual[1] = T(1.0) - x1;
-  residual[2] = T(sqrt(90.0)) * (x4 - x3 * x3);
-  residual[3] = T(1.0) - x3;
-  residual[4] = T(sqrt(10.0)) * (x2 + x4 - T(2.0));
-  residual[5] = T(1.0/sqrt(10.0)) * (x2 - x4);
+  residual[0] = 10.0 * (x2 - x1 * x1);
+  residual[1] = 1.0 - x1;
+  residual[2] = sqrt(90.0) * (x4 - x3 * x3);
+  residual[3] = 1.0 - x3;
+  residual[4] = sqrt(10.0) * (x2 + x4 - 2.0);
+  residual[5] = 1.0 / sqrt(10.0) * (x2 - x4);
 END_MGH_PROBLEM;
 
-const double TestProblem14::initial_x[] = {-3.0, -1.0, -3.0, -1.0};
-const double TestProblem14::lower_bounds[] = {-100.0, -100.0, -100.0, -100.0};
-const double TestProblem14::upper_bounds[] = {0.0, 10.0, 100.0, 100.0};
-const double TestProblem14::constrained_optimal_cost = 0.15567008e1;
-const double TestProblem14::unconstrained_optimal_cost = 0.0;
+  const double TestProblem14::initial_x[] = {-3.0, -1.0, -3.0, -1.0};
+  const double TestProblem14::lower_bounds[] = {-100.0, -100.0, -100.0, -100.0};
+  const double TestProblem14::upper_bounds[] = {0.0, 10.0, 100.0, 100.0};
+  const double TestProblem14::constrained_optimal_cost = 0.15567008e1;
+  const double TestProblem14::unconstrained_optimal_cost = 0.0;
 
-// Kowalik and Osborne function.
-BEGIN_MGH_PROBLEM(TestProblem15, 4, 11)
+  // Kowalik and Osborne function.
+  BEGIN_MGH_PROBLEM(TestProblem15, 4, 11)
   const T x1 = x[0];
   const T x2 = x[1];
   const T x3 = x[2];
@@ -401,9 +399,7 @@
                       0.0833, 0.0714, 0.0625};
 
   for (int i = 0; i < 11; ++i) {
-    const T yi = T(y[i]);
-    const T ui = T(u[i]);
-    residual[i]  = yi - x1 * (ui * ui + ui * x2) / (ui * ui  + ui * x3 + x4);
+    residual[i]  = y[i] - x1 * (u[i] * u[i] + u[i] * x2) / (u[i] * u[i]  + u[i] * x3 + x4);
   }
 END_MGH_PROBLEM;
 
@@ -424,7 +420,7 @@
   const T x4 = x[3];
 
   for (int i = 0; i < 20; ++i) {
-    const T ti = T(static_cast<double>(i + 1) / 5.0);
+    const double ti = static_cast<double>(i + 1) / 5.0;
     residual[i] = (x1 + ti * x2 - exp(ti)) * (x1 + ti * x2 - exp(ti)) +
         (x3 + x4 * sin(ti) - cos(ti)) * (x3 + x4 * sin(ti) - cos(ti));
   }
@@ -450,9 +446,8 @@
                       0.431, 0.424, 0.420, 0.414, 0.411, 0.406};
 
   for (int i = 0; i < 33; ++i) {
-    const T yi = T(y[i]);
-    const T ti = T(10.0 * i);
-    residual[i] = yi - (x1 + x2 * exp(-ti * x4) + x3 * exp(-ti * x5));
+     const double ti = 10.0 * i;
+    residual[i] = y[i] - (x1 + x2 * exp(-ti * x4) + x3 * exp(-ti * x5));
   }
 END_MGH_PROBLEM;
 
@@ -477,8 +472,7 @@
   for (int i = 0; i < 13; ++i) {
     const double ti = 0.1 * (i + 1.0);
     const double yi = exp(-ti) - 5.0 * exp(-10.0 * ti) + 3.0 * exp(-4.0 * ti);
-    const T si = T(ti);
-    residual[i] =x3 * exp(-si * x1) - x4 * exp(-si * x2) + x6 * exp(-si * x5) - T(yi);
+    residual[i] =x3 * exp(-ti * x1) - x4 * exp(-ti * x2) + x6 * exp(-ti * x5) - yi;
   }
 END_MGH_PROBLEM
 
@@ -517,11 +511,11 @@
                       0.428, 0.292, 0.162, 0.098, 0.054};
 
   for (int i = 0; i < 65; ++i) {
-    const T ti = T(static_cast<double>(i) / 10.0);
-    residual[i] = T(y[i]) - (x1 * exp(-(ti * x5)) +
-                             x2 * exp(-(ti - x9)  * (ti - x9)  * x6) +
-                             x3 * exp(-(ti - x10) * (ti - x10) * x7) +
-                             x4 * exp(-(ti - x11) * (ti - x11) * x8));
+    const double ti = static_cast<double>(i) / 10.0;
+    residual[i] = y[i] - (x1 * exp(-(ti * x5)) +
+                          x2 * exp(-(ti - x9)  * (ti - x9)  * x6) +
+                          x3 * exp(-(ti - x10) * (ti - x10) * x7) +
+                          x4 * exp(-(ti - x11) * (ti - x11) * x8));
   }
 END_MGH_PROBLEM;
 
diff --git a/examples/nist.cc b/examples/nist.cc
index 4b640fe..55a3c7c 100644
--- a/examples/nist.cc
+++ b/examples/nist.cc
@@ -180,6 +180,7 @@
  public:
   explicit NISTProblem(const string& filename) {
     ifstream ifs(filename.c_str(), ifstream::in);
+    CHECK(ifs) << "Unable to open : " << filename;
 
     vector<string> pieces;
     SkipLines(ifs, 24);
@@ -281,12 +282,12 @@
 
 // y = b1 * (b2+x)**(-1/b3)  +  e
 NIST_BEGIN(Bennet5)
-  b[0] * pow(b[1] + x, T(-1.0) / b[2])
+  b[0] * pow(b[1] + x, -1.0 / b[2])
 NIST_END
 
 // y = b1*(1-exp[-b2*x])  +  e
 NIST_BEGIN(BoxBOD)
-  b[0] * (T(1.0) - exp(-b[1] * x))
+  b[0] * (1.0 - exp(-b[1] * x))
 NIST_END
 
 // y = exp[-b1*x]/(b2+b3*x)  +  e
@@ -316,14 +317,14 @@
 //     (1+b5*x+b6*x**2+b7*x**3)  +  e
 NIST_BEGIN(Hahn1)
   (b[0] + b[1] * x + b[2] * x * x + b[3] * x * x * x) /
-  (T(1.0) + b[4] * x + b[5] * x * x + b[6] * x * x * x)
+  (1.0 + b[4] * x + b[5] * x * x + b[6] * x * x * x)
 NIST_END
 
 // y = (b1 + b2*x + b3*x**2) /
 //    (1 + b4*x + b5*x**2)  +  e
 NIST_BEGIN(Kirby2)
   (b[0] + b[1] * x + b[2] * x * x) /
-  (T(1.0) + b[3] * x + b[4] * x * x)
+  (1.0 + b[3] * x + b[4] * x * x)
 NIST_END
 
 // y = b1*(x**2+x*b2) / (x**2+x*b3+b4)  +  e
@@ -343,63 +344,63 @@
 
 // y = b1*(1-exp[-b2*x])  +  e
 NIST_BEGIN(Misra1a)
-  b[0] * (T(1.0) - exp(-b[1] * x))
+  b[0] * (1.0 - exp(-b[1] * x))
 NIST_END
 
 // y = b1 * (1-(1+b2*x/2)**(-2))  +  e
 NIST_BEGIN(Misra1b)
-  b[0] * (T(1.0) - T(1.0)/ ((T(1.0) + b[1] * x / 2.0) * (T(1.0) + b[1] * x / 2.0)))  // NOLINT
+  b[0] * (1.0 - 1.0/ ((1.0 + b[1] * x / 2.0) * (1.0 + b[1] * x / 2.0)))  // NOLINT
 NIST_END
 
 // y = b1 * (1-(1+2*b2*x)**(-.5))  +  e
 NIST_BEGIN(Misra1c)
-  b[0] * (T(1.0) - pow(T(1.0) + T(2.0) * b[1] * x, -0.5))
+  b[0] * (1.0 - pow(1.0 + 2.0 * b[1] * x, -0.5))
 NIST_END
 
 // y = b1*b2*x*((1+b2*x)**(-1))  +  e
 NIST_BEGIN(Misra1d)
-  b[0] * b[1] * x / (T(1.0) + b[1] * x)
+  b[0] * b[1] * x / (1.0 + b[1] * x)
 NIST_END
 
 const double kPi = 3.141592653589793238462643383279;
 // pi = 3.141592653589793238462643383279E0
 // y =  b1 - b2*x - arctan[b3/(x-b4)]/pi  +  e
 NIST_BEGIN(Roszman1)
-  b[0] - b[1] * x - atan2(b[2], (x - b[3]))/T(kPi)
+  b[0] - b[1] * x - atan2(b[2], (x - b[3])) / kPi
 NIST_END
 
 // y = b1 / (1+exp[b2-b3*x])  +  e
 NIST_BEGIN(Rat42)
-  b[0] / (T(1.0) + exp(b[1] - b[2] * x))
+  b[0] / (1.0 + exp(b[1] - b[2] * x))
 NIST_END
 
 // y = b1 / ((1+exp[b2-b3*x])**(1/b4))  +  e
 NIST_BEGIN(Rat43)
-  b[0] / pow(T(1.0) + exp(b[1] - b[2] * x), T(1.0) / b[3])
+  b[0] / pow(1.0 + exp(b[1] - b[2] * x), 1.0 / b[3])
 NIST_END
 
 // y = (b1 + b2*x + b3*x**2 + b4*x**3) /
 //    (1 + b5*x + b6*x**2 + b7*x**3)  +  e
 NIST_BEGIN(Thurber)
   (b[0] + b[1] * x + b[2] * x * x  + b[3] * x * x * x) /
-  (T(1.0) + b[4] * x + b[5] * x * x + b[6] * x * x * x)
+  (1.0 + b[4] * x + b[5] * x * x + b[6] * x * x * x)
 NIST_END
 
 // y = b1 + b2*cos( 2*pi*x/12 ) + b3*sin( 2*pi*x/12 )
 //        + b5*cos( 2*pi*x/b4 ) + b6*sin( 2*pi*x/b4 )
 //        + b8*cos( 2*pi*x/b7 ) + b9*sin( 2*pi*x/b7 )  + e
 NIST_BEGIN(ENSO)
-  b[0] + b[1] * cos(T(2.0 * kPi) * x / T(12.0)) +
-         b[2] * sin(T(2.0 * kPi) * x / T(12.0)) +
-         b[4] * cos(T(2.0 * kPi) * x / b[3]) +
-         b[5] * sin(T(2.0 * kPi) * x / b[3]) +
-         b[7] * cos(T(2.0 * kPi) * x / b[6]) +
-         b[8] * sin(T(2.0 * kPi) * x / b[6])
+  b[0] + b[1] * cos(2.0 * kPi * x / 12.0) +
+         b[2] * sin(2.0 * kPi * x / 12.0) +
+         b[4] * cos(2.0 * kPi * x / b[3]) +
+         b[5] * sin(2.0 * kPi * x / b[3]) +
+         b[7] * cos(2.0 * kPi * x / b[6]) +
+         b[8] * sin(2.0 * kPi * x / b[6])
 NIST_END
 
 // y = (b1/b2) * exp[-0.5*((x-b3)/b2)**2]  +  e
 NIST_BEGIN(Eckerle4)
-  b[0] / b[1] * exp(T(-0.5) * pow((x - b[2])/b[1], 2))
+  b[0] / b[1] * exp(-0.5 * pow((x - b[2])/b[1], 2))
 NIST_END
 
 struct Nelson {
@@ -410,7 +411,7 @@
   template <typename T>
   bool operator()(const T* const b, T* residual) const {
     // log[y] = b1 - b2*x1 * exp[-b3*x2]  +  e
-    residual[0] = T(log(y_)) - (b[0] - b[1] * T(x1_) * exp(-b[2] * T(x2_)));
+    residual[0] = log(y_) - (b[0] - b[1] * x1_ * exp(-b[2] * x2_));
     return true;
   }
 
@@ -425,10 +426,26 @@
   options->ridders_relative_initial_step_size = FLAGS_ridders_step_size;
 }
 
+string JoinPath(const string& dirname, const string& basename) {
+#ifdef _WIN32
+    static const char separator = '\\';
+#else
+    static const char separator = '/';
+#endif  // _WIN32
+
+  if ((!basename.empty() && basename[0] == separator) || dirname.empty()) {
+    return basename;
+  } else if (dirname[dirname.size() - 1] == separator) {
+    return dirname + basename;
+  } else {
+    return dirname + string(&separator, 1) + basename;
+  }
+}
+
 template <typename Model, int num_residuals, int num_parameters>
 int RegressionDriver(const string& filename,
                      const ceres::Solver::Options& options) {
-  NISTProblem nist_problem(FLAGS_nist_data_dir + filename);
+  NISTProblem nist_problem(JoinPath(FLAGS_nist_data_dir, filename));
   CHECK_EQ(num_residuals, nist_problem.response_size());
   CHECK_EQ(num_parameters, nist_problem.num_parameters());
 
diff --git a/examples/powell.cc b/examples/powell.cc
index baaa149..e98f12f 100644
--- a/examples/powell.cc
+++ b/examples/powell.cc
@@ -60,7 +60,7 @@
                                         const T* const x2,
                                         T* residual) const {
     // f1 = x1 + 10 * x2;
-    residual[0] = x1[0] + T(10.0) * x2[0];
+    residual[0] = x1[0] + 10.0 * x2[0];
     return true;
   }
 };
@@ -70,7 +70,7 @@
                                         const T* const x4,
                                         T* residual) const {
     // f2 = sqrt(5) (x3 - x4)
-    residual[0] = T(sqrt(5.0)) * (x3[0] - x4[0]);
+    residual[0] = sqrt(5.0) * (x3[0] - x4[0]);
     return true;
   }
 };
@@ -80,7 +80,7 @@
                                         const T* const x4,
                                         T* residual) const {
     // f3 = (x2 - 2 x3)^2
-    residual[0] = (x2[0] - T(2.0) * x4[0]) * (x2[0] - T(2.0) * x4[0]);
+    residual[0] = (x2[0] - 2.0 * x4[0]) * (x2[0] - 2.0 * x4[0]);
     return true;
   }
 };
@@ -90,7 +90,7 @@
                                         const T* const x4,
                                         T* residual) const {
     // f4 = sqrt(10) (x1 - x4)^2
-    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;
   }
 };
diff --git a/examples/robot_pose_mle.cc b/examples/robot_pose_mle.cc
index f08603a..1f5058a 100644
--- a/examples/robot_pose_mle.cc
+++ b/examples/robot_pose_mle.cc
@@ -170,7 +170,7 @@
 
   template <typename T>
   bool operator()(const T* const odometry, T* residual) const {
-    *residual = (*odometry - T(odometry_mean)) / T(odometry_stddev);
+    *residual = (*odometry - odometry_mean) / odometry_stddev;
     return true;
   }
 
@@ -201,8 +201,8 @@
     for (int i = 0; i <= pose_index; ++i) {
       global_pose += relative_poses[i][0];
     }
-    residuals[0] = (global_pose + T(range_reading) - T(corridor_length)) /
-        T(range_stddev);
+    residuals[0] = (global_pose + range_reading - corridor_length) /
+        range_stddev;
     return true;
   }
 
diff --git a/examples/robust_curve_fitting.cc b/examples/robust_curve_fitting.cc
index 67aca03..6186aa1 100644
--- a/examples/robust_curve_fitting.cc
+++ b/examples/robust_curve_fitting.cc
@@ -127,7 +127,7 @@
   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;
   }
 
diff --git a/examples/simple_bundle_adjuster.cc b/examples/simple_bundle_adjuster.cc
index 8b98852..dec6cd6 100644
--- a/examples/simple_bundle_adjuster.cc
+++ b/examples/simple_bundle_adjuster.cc
@@ -146,7 +146,7 @@
     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];
@@ -154,8 +154,8 @@
     T predicted_y = focal * distortion * yp;
 
     // The error is the difference between the predicted and observed position.
-    residuals[0] = predicted_x - T(observed_x);
-    residuals[1] = predicted_y - T(observed_y);
+    residuals[0] = predicted_x - observed_x;
+    residuals[1] = predicted_y - observed_y;
 
     return true;
   }
diff --git a/examples/snavely_reprojection_error.h b/examples/snavely_reprojection_error.h
index a425616..5e51eb4 100644
--- a/examples/snavely_reprojection_error.h
+++ b/examples/snavely_reprojection_error.h
@@ -77,7 +77,7 @@
     const T& l1 = camera[7];
     const T& l2 = camera[8];
     const T r2 = xp*xp + yp*yp;
-    const T distortion = T(1.0) + r2  * (l1 + l2  * r2);
+    const T distortion = 1.0 + r2  * (l1 + l2  * r2);
 
 
     // Compute final projected point position.
@@ -86,8 +86,8 @@
     const T predicted_y = focal * distortion * yp;
 
     // The error is the difference between the predicted and observed position.
-    residuals[0] = predicted_x - T(observed_x);
-    residuals[1] = predicted_y - T(observed_y);
+    residuals[0] = predicted_x - observed_x;
+    residuals[1] = predicted_y - observed_y;
 
     return true;
   }
@@ -143,7 +143,7 @@
     const T& l2 = camera[9];
 
     const T r2 = xp*xp + yp*yp;
-    const T distortion = T(1.0) + r2  * (l1 + l2  * r2);
+    const T distortion = 1.0 + r2  * (l1 + l2  * r2);
 
     // Compute final projected point position.
     const T& focal = camera[7];
@@ -151,8 +151,8 @@
     const T predicted_y = focal * distortion * yp;
 
     // The error is the difference between the predicted and observed position.
-    residuals[0] = predicted_x - T(observed_x);
-    residuals[1] = predicted_y - T(observed_y);
+    residuals[0] = predicted_x - observed_x;
+    residuals[1] = predicted_y - observed_y;
 
     return true;
   }
diff --git a/internal/ceres/bundle_adjustment_test.cc b/internal/ceres/bundle_adjustment_test.cc
index 5cf2be0..7cbf3f3 100644
--- a/internal/ceres/bundle_adjustment_test.cc
+++ b/internal/ceres/bundle_adjustment_test.cc
@@ -212,8 +212,8 @@
       T r2 = xp*xp + yp*yp;
       T distortion = T(1.0) + r2  * (l1 + l2  * r2);
 
-      residuals[0] = distortion * xp - T(u);
-      residuals[1] = distortion * yp - T(v);
+      residuals[0] = distortion * xp - u;
+      residuals[1] = distortion * yp - v;
 
       return true;
     }
diff --git a/internal/ceres/system_test.cc b/internal/ceres/system_test.cc
index 5fb608e..de03c74 100644
--- a/internal/ceres/system_test.cc
+++ b/internal/ceres/system_test.cc
@@ -98,7 +98,7 @@
                                           const T* const x2,
                                           T* residual) const {
       // f1 = x1 + 10 * x2;
-      *residual = *x1 + T(10.0) * *x2;
+      *residual = *x1 + 10.0 * *x2;
       return true;
     }
   };
@@ -109,7 +109,7 @@
                                           const T* const x4,
                                           T* residual) const {
       // f2 = sqrt(5) (x3 - x4)
-      *residual = T(sqrt(5.0)) * (*x3 - *x4);
+      *residual = std::sqrt(5.0) * (*x3 - *x4);
       return true;
     }
   };
@@ -120,7 +120,7 @@
                                           const T* const x4,
                                           T* residual) const {
       // f3 = (x2 - 2 x3)^2
-      residual[0] = (x2[0] - T(2.0) * x4[0]) * (x2[0] - T(2.0) * x4[0]);
+      residual[0] = (x2[0] - 2.0 * x4[0]) * (x2[0] - 2.0 * x4[0]);
       return true;
     }
   };
@@ -131,7 +131,7 @@
                                           const T* const x4,
                                           T* residual) const {
       // f4 = sqrt(10) (x1 - x4)^2
-      residual[0] = T(sqrt(10.0)) * (x1[0] - x4[0]) * (x1[0] - x4[0]);
+      residual[0] = std::sqrt(10.0) * (x1[0] - x4[0]) * (x1[0] - x4[0]);
       return true;
     }
   };