Added some missing "explicit" keywords.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%403781

dlib/optimization/optimization_search_strategies.h

@@ -154,7 +154,7 @@ namespace dlib
     class lbfgs_search_strategy
     {
     public:
-        lbfgs_search_strategy(unsigned long max_size_) : max_size(max_size_), been_used(false) 
+        explicit lbfgs_search_strategy(unsigned long max_size_) : max_size(max_size_), been_used(false) 
         {
             DLIB_ASSERT (
                 max_size > 0,
@@ -284,7 +284,7 @@ namespace dlib
     class newton_search_strategy_obj
     {
     public:
-        newton_search_strategy_obj(
+        explicit newton_search_strategy_obj(
             const hessian_funct& hess
         ) : hessian(hess) {}
 

dlib/optimization/optimization_search_strategies_abstract.h

@@ -172,7 +172,7 @@ namespace dlib
                 to use when an optimization problem has a large number of variables.
         !*/
     public:
-        lbfgs_search_strategy(
+        explicit lbfgs_search_strategy(
             unsigned long max_size
         ); 
         /*!
@@ -254,7 +254,7 @@ namespace dlib
                     search_direction = -inv(hessian(x))*derivative
         !*/
     public:
-        newton_search_strategy_obj(
+        explicit newton_search_strategy_obj(
             const hessian_funct& hess
         ); 
         /*!

dlib/optimization/optimization_stop_strategies.h

@@ -18,7 +18,7 @@ namespace dlib
     class objective_delta_stop_strategy
     {
     public:
-        objective_delta_stop_strategy (
+        explicit objective_delta_stop_strategy (
             double min_delta = 1e-7
         ) : _verbose(false), _been_used(false), _min_delta(min_delta), _max_iter(0), _cur_iter(0), _prev_funct_value(0) 
         {
@@ -97,7 +97,7 @@ namespace dlib
     class gradient_norm_stop_strategy
     {
     public:
-        gradient_norm_stop_strategy (
+        explicit gradient_norm_stop_strategy (
             double min_norm = 1e-7
         ) : _verbose(false), _min_norm(min_norm), _max_iter(0), _cur_iter(0) 
         {

dlib/optimization/optimization_stop_strategies_abstract.h

@@ -26,7 +26,7 @@ namespace dlib
         !*/
 
     public:
-        objective_delta_stop_strategy (
+        explicit objective_delta_stop_strategy (
             double min_delta = 1e-7
         ); 
         /*!
@@ -95,7 +95,7 @@ namespace dlib
         !*/
 
     public:
-        gradient_norm_stop_strategy (
+        explicit gradient_norm_stop_strategy (
             double min_norm = 1e-7
         ); 
         /*!