differential std::clamp from c++17 with dlib:: prefix to clamp() (#734)

dlib/control/mpc.h

@@ -339,8 +339,8 @@ namespace dlib
                     for (unsigned long i = 0; i < horizon; ++i)
                     {
                         v_old[i] = v[i];
-                        v[i] = clamp(controls[i] - 1.0/lambda * df[i], lower, upper);
-                        controls[i] = clamp(v[i] + (std::sqrt(lambda)-1)/(std::sqrt(lambda)+1)*(v[i]-v_old[i]), lower, upper);
+                        v[i] = dlib::clamp(controls[i] - 1.0/lambda * df[i], lower, upper);
+                        controls[i] = dlib::clamp(v[i] + (std::sqrt(lambda)-1)/(std::sqrt(lambda)+1)*(v[i]-v_old[i]), lower, upper);
                     }
                 }
             }

dlib/matrix/matrix_la.h

@@ -1646,7 +1646,7 @@ convergence:
         if (dot(delta, g) < 0)
             return p;
         else
-            return vector<double,2>(p)+clamp(delta, -1, 1);
+            return vector<double,2>(p)+dlib::clamp(delta, -1, 1);
     }
 
 // ----------------------------------------------------------------------------------------

dlib/optimization/optimization.h

@@ -527,7 +527,7 @@ namespace dlib
                 last_alpha = alpha;
 
             // Take the search step indicated by the above line search
-            x = clamp(x + alpha*s, x_lower, x_upper);
+            x = dlib::clamp(x + alpha*s, x_lower, x_upper);
             g = der(x);
 
             if (!is_finite(f_value))
@@ -658,7 +658,7 @@ namespace dlib
                 last_alpha = alpha;
 
             // Take the search step indicated by the above line search
-            x = clamp(x + alpha*s, x_lower, x_upper);
+            x = dlib::clamp(x + alpha*s, x_lower, x_upper);
             g = -der(x);
 
             // Don't forget to negate the output from the line search since it is  from the

dlib/optimization/optimization_solve_qp_using_smo.h

@@ -286,7 +286,7 @@ namespace dlib
             lambda = A*alpha;
         else
             lambda = A*alpha + d;
-        lambda = clamp(lambda, 0, max_lambda);
+        lambda = dlib::clamp(lambda, 0, max_lambda);
 
         // Compute f'(alpha) (i.e. the gradient of f(alpha) with respect to alpha) for the current alpha.  
         matrix<T,NR,NC,MM,L> df = Q*alpha - b - trans(A)*lambda;
@@ -333,7 +333,7 @@ namespace dlib
                     lambda = A*alpha;
                 else
                     lambda = A*alpha + d;
-                lambda = clamp(lambda, 0, max_lambda);
+                lambda = dlib::clamp(lambda, 0, max_lambda);
                 df = Q*alpha - b - trans(A)*lambda;
 
                 if (trans(alpha)*df - C*min(df) < eps)
@@ -375,7 +375,7 @@ namespace dlib
                     lambda = A*alpha;
                 else
                     lambda = A*alpha + d;
-                lambda = clamp(lambda, 0, max_lambda);
+                lambda = dlib::clamp(lambda, 0, max_lambda);
 
                 // Perform this form of the update every so often because doing so can help
                 // avoid the buildup of numerical errors you get with the alternate update
@@ -524,7 +524,7 @@ namespace dlib
             df = Q*alpha + b;
             // now take a projected gradient step using Nesterov's method.
             v = clamp(alpha - 1.0/lipschitz_bound * df, lower, upper);
-            alpha = clamp((1-gamma)*v + gamma*v_old, lower, upper);
+            alpha = dlib::clamp((1-gamma)*v + gamma*v_old, lower, upper);
 
 
             // check for convergence every 10 iterations

dlib/test/matrix2.cpp

@@ -379,23 +379,23 @@ namespace
             u = 2,2.2;
 
             out = 2, 2.2;
-            DLIB_TEST(equal(clamp(x, l, u) , out));
+            DLIB_TEST(equal(dlib::clamp(x, l, u) , out));
             out = 3, 2.2;
-            DLIB_TEST(!equal(clamp(x, l, u) , out));
+            DLIB_TEST(!equal(dlib::clamp(x, l, u) , out));
             out = 2, 4.2;
-            DLIB_TEST(!equal(clamp(x, l, u) , out));
+            DLIB_TEST(!equal(dlib::clamp(x, l, u) , out));
 
             x = 1.5, 1.5;
             out = x;
-            DLIB_TEST(equal(clamp(x, l, u) , out));
+            DLIB_TEST(equal(dlib::clamp(x, l, u) , out));
 
             x = 0.5, 1.5;
             out = 1, 1.5;
-            DLIB_TEST(equal(clamp(x, l, u) , out));
+            DLIB_TEST(equal(dlib::clamp(x, l, u) , out));
 
             x = 1.5, 0.5;
             out = 1.5, 1.0;
-            DLIB_TEST(equal(clamp(x, l, u) , out));
+            DLIB_TEST(equal(dlib::clamp(x, l, u) , out));
 
         }