types: rename why() to what() in exception classes

Signed-off-by: Paweł Dziepak <pdziepak@cloudius-systems.com>

cql3/maps.cc

@@ -152,7 +152,7 @@ maps::value::from_serialized(bytes_view value, map_type type, serialization_form
         }
         return { std::move(map) };
     } catch (marshal_exception& e) {
-        throw exceptions::invalid_request_exception(e.why());
+        throw exceptions::invalid_request_exception(e.what());
     }
 }
 

cql3/sets.cc

@@ -115,7 +115,7 @@ sets::value::from_serialized(bytes_view v, set_type type, serialization_format s
         }
         return value(std::move(elements));
     } catch (marshal_exception& e) {
-        throw exceptions::invalid_request_exception(e.why());
+        throw exceptions::invalid_request_exception(e.what());
     }
 }
 

types.hh

@@ -152,14 +152,14 @@ class marshal_exception : public std::exception {
 public:
     marshal_exception() : _why("marshalling error") {}
     marshal_exception(sstring why) : _why(sstring("marshaling error: ") + why) {}
-    virtual const char* why() const { return _why.c_str(); }
+    virtual const char* what() const noexcept override { return _why.c_str(); }
 };
 
 struct runtime_exception : public std::exception {
     sstring _why;
 public:
     runtime_exception(sstring why) : _why(sstring("runtime error: ") + why) {}
-    virtual const char* why() const { return _why.c_str(); }
+    virtual const char* what() const noexcept override { return _why.c_str(); }
 };
 
 inline int32_t compare_unsigned(bytes_view v1, bytes_view v2) {

validation.cc

@@ -46,7 +46,7 @@ validate_cql_key(schema_ptr schema, const partition_key& key) {
     try {
         schema->partition_key_type()->validate(b);
     } catch (const marshal_exception& e) {
-        throw exceptions::invalid_request_exception(e.why());
+        throw exceptions::invalid_request_exception(e.what());
     }
 }