Misc places : Add [[fallthrough]] where appropriate

Author: danieldresser

include/IECore/MurmurHash.inl

@@ -125,23 +125,37 @@ inline void MurmurHash::appendRaw( const void *data, size_t bytes, int elementSi
 	switch( bytes & 15)
 	{
 	case 15: k2 ^= uint64_t(tail[14]) << 48;
+		[[fallthrough]];
 	case 14: k2 ^= uint64_t(tail[13]) << 40;
+		[[fallthrough]];
 	case 13: k2 ^= uint64_t(tail[12]) << 32;
+		[[fallthrough]];
 	case 12: k2 ^= uint64_t(tail[11]) << 24;
+		[[fallthrough]];
 	case 11: k2 ^= uint64_t(tail[10]) << 16;
+		[[fallthrough]];
 	case 10: k2 ^= uint64_t(tail[ 9]) << 8;
+		[[fallthrough]];
 	case  9: k2 ^= uint64_t(tail[ 8]) << 0;
-		   k2 *= c2; k2  = rotl64(k2,33); k2 *= c1; h2 ^= k2;
+		k2 *= c2; k2  = rotl64(k2,33); k2 *= c1; h2 ^= k2;
+		[[fallthrough]];
 
 	case  8: k1 ^= uint64_t(tail[ 7]) << 56;
+		[[fallthrough]];
 	case  7: k1 ^= uint64_t(tail[ 6]) << 48;
+		[[fallthrough]];
 	case  6: k1 ^= uint64_t(tail[ 5]) << 40;
+		[[fallthrough]];
 	case  5: k1 ^= uint64_t(tail[ 4]) << 32;
+		[[fallthrough]];
 	case  4: k1 ^= uint64_t(tail[ 3]) << 24;
+		[[fallthrough]];
 	case  3: k1 ^= uint64_t(tail[ 2]) << 16;
+		[[fallthrough]];
 	case  2: k1 ^= uint64_t(tail[ 1]) << 8;
+		[[fallthrough]];
 	case  1: k1 ^= uint64_t(tail[ 0]) << 0;
-		   k1 *= c1; k1  = rotl64(k1,31); k1 *= c2; h1 ^= k1;
+		k1 *= c1; k1  = rotl64(k1,31); k1 *= c2; h1 ^= k1;
 	};
 
 	// finalisation

include/IECore/StringAlgo.inl

@@ -76,12 +76,11 @@ inline bool matchCharacterClass( char c, const char *&pattern )
 					}
 					continue;
 				}
-				else
-				{
-					// The '-' was at the start or end of the
-					// pattern, fall through to treat it
-					// as a regular character below.
-				}
+
+				// The '-' was at the start or end of the
+				// pattern, fall through to treat it
+				// as a regular character below.
+				[[fallthrough]];
 			default :
 				if( d == c )
 				{
@@ -160,7 +159,7 @@ inline bool matchInternal( const char *s, const char *&pattern, bool spaceTermin
 					return *s == '\0';
 				}
 				// Fall through to default
-
+				[[fallthrough]];
 			default :
 
 				if( c != *s++ )

src/IECoreScene/PDCParticleWriter.cpp

@@ -188,6 +188,7 @@ void PDCParticleWriter::doWrite( const CompoundObject *operands )
 					castOp.targetTypeParameter()->setNumericValue( DoubleVectorDataTypeId );
 					attr = boost::static_pointer_cast<DoubleVectorData>( castOp.operate() );
 				} // intentionally falling through
+				[[fallthrough]];
 			case DoubleVectorDataTypeId :
 				{
 					int type = 3; type = asBigEndian( type );
@@ -204,6 +205,7 @@ void PDCParticleWriter::doWrite( const CompoundObject *operands )
 					castOp.targetTypeParameter()->setNumericValue( V3dVectorDataTypeId );
 					attr = boost::static_pointer_cast<V3dVectorData>( castOp.operate() );
 				} // intentionally falling through
+				[[fallthrough]];
 			case V3dVectorDataTypeId :
 				{
 					int type = 5; type = asBigEndian( type );
@@ -227,6 +229,7 @@ void PDCParticleWriter::doWrite( const CompoundObject *operands )
 					castOp.targetTypeParameter()->setNumericValue( DoubleDataTypeId );
 					attr = boost::static_pointer_cast<DoubleData>( castOp.operate() );
 				} // intentionally falling through
+				[[fallthrough]];
 			case DoubleDataTypeId :
 				{
 					int type = 2; type = asBigEndian( type );
@@ -243,6 +246,7 @@ void PDCParticleWriter::doWrite( const CompoundObject *operands )
 					castOp.targetTypeParameter()->setNumericValue( V3dDataTypeId );
 					attr = boost::static_pointer_cast<V3dData>( castOp.operate() );
 				} // intentionally falling through
+				[[fallthrough]];
 			case V3dDataTypeId :
 				{
 					int type = 4; type = asBigEndian( type );