Add generic version of getXxxValue

This allows us to call getIntegerValue/getFloatingPointValue from
generic code where the type to be used is a template parameter.

opm/core/io/eclipse/EclipseGridParser.cpp

@@ -1178,4 +1178,16 @@ void EclipseGridParser::getNumericErtFields(const string& filename)
 #endif  // HAVE_ERT
 }
 
+// specializations for those types that can be provided; attempts
+// to access other types than these will result in linker error
+template <> const std::vector<int>&
+EclipseGridParser::getValue<int> (const std::string& keyword) const {
+    return this->getIntegerValue(keyword);
+}
+
+template <> const std::vector<double>&
+EclipseGridParser::getValue<double> (const std::string& keyword) const {
+    return this->getFloatingPointValue(keyword);
+}
+
 } // namespace Opm

opm/core/io/eclipse/EclipseGridParser.hpp

@@ -138,6 +138,12 @@ namespace Opm
     /// corresponding to the given floating-point keyword.
     const std::vector<double>& getFloatingPointValue(const std::string& keyword) const;
 
+    /// Returns a reference to a vector containing the values
+    /// corresponding to the given keyword of a type only known
+    /// indirectly (through a template)
+    template <typename T>
+    const std::vector<T>& getValue(const std::string& keyword) const;
+
     typedef std::shared_ptr<SpecialBase> SpecialFieldPtr;
 
     /// Returns a reference to a vector containing pointers to the values