[functions.expression] use lock_guard and fix merge error

dune/stuff/functions/expression.hh

@@ -237,7 +237,7 @@ public:
                          << function_->variable()
                          << "\n"
                          << "The expression of this functional is: "
-                         << expression().at(rr * dimRangeCols + cc)
+                         << function_->expression().at(rr * dimRangeCols + cc)
                          << "\n"
                          << "You tried to evaluate it with:   xx = "
                          << xx

dune/stuff/functions/expression/base.hh

@@ -86,14 +86,13 @@ public:
   void evaluate(const Dune::FieldVector<DomainFieldType, dimDomain>& arg,
                 Dune::FieldVector<RangeFieldType, dimRange>& ret) const
   {
-    mutex_.lock();
+    std::lock_guard<std::mutex> guard(mutex_);
     // copy arg
     for (typename Dune::FieldVector<DomainFieldType, dimDomain>::size_type ii = 0; ii < dimDomain; ++ii)
       *(arg_[ii]) = arg[ii];
     // copy ret
     for (typename Dune::FieldVector<RangeFieldType, dimRange>::size_type ii = 0; ii < dimRange; ++ii)
       ret[ii] = op_[ii]->Val();
-    mutex_.unlock();
   }
 
   /**
@@ -101,7 +100,7 @@ public:
    */
   void evaluate(const Dune::DynamicVector<DomainFieldType>& arg, Dune::DynamicVector<RangeFieldType>& ret) const
   {
-    mutex_.lock();
+    std::lock_guard<std::mutex> guard(mutex_);
     // check for sizes
     assert(arg.size() > 0);
     if (ret.size() != dimRange)
@@ -112,13 +111,12 @@ public:
     // copy ret
     for (typename Dune::DynamicVector<RangeFieldType>::size_type ii = 0; ii < dimRange; ++ii)
       ret[ii] = op_[ii]->Val();
-    mutex_.unlock();
   }
 
   void evaluate(const Dune::FieldVector<DomainFieldType, dimDomain>& arg,
                 Dune::DynamicVector<RangeFieldType>& ret) const
   {
-    mutex_.lock();
+    std::lock_guard<std::mutex> guard(mutex_);
     // check for sizes
     if (ret.size() != dimRange)
       ret = Dune::DynamicVector<RangeFieldType>(dimRange);
@@ -128,7 +126,6 @@ public:
     // copy ret
     for (typename Dune::DynamicVector<RangeFieldType>::size_type ii = 0; ii < dimRange; ++ii)
       ret[ii] = op_[ii]->Val();
-    mutex_.unlock();
   }
 
   /**
@@ -136,7 +133,7 @@ public:
    */
   void evaluate(const Dune::DynamicVector<DomainFieldType>& arg, Dune::FieldVector<RangeFieldType, dimRange>& ret) const
   {
-    mutex_.lock();
+    std::lock_guard<std::mutex> guard(mutex_);
     assert(arg.size() > 0);
     // copy arg
     for (size_t ii = 0; ii < std::min(dimDomain, arg.size()); ++ii)
@@ -144,7 +141,6 @@ public:
     // copy ret
     for (size_t ii = 0; ii < dimRange; ++ii)
       ret[ii] = op_[ii]->Val();
-    mutex_.unlock();
   }
 
   void report(const std::string _name = "dune.stuff.function.mathexpressionbase", std::ostream& stream = std::cout,