ImageEngine · johnhaddon · Mar 19, 2026
diff --git a/contrib/IECoreAlembic/include/IECoreAlembic/AlembicScene.h b/contrib/IECoreAlembic/include/IECoreAlembic/AlembicScene.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREALEMBIC_ALEMBICSCENE_H
-#define IECOREALEMBIC_ALEMBICSCENE_H
+#pragma once
 
 #include "IECoreAlembic/Export.h"
 #include "IECoreAlembic/TypeIds.h"
@@ -126,5 +125,3 @@ class IECOREALEMBIC_API AlembicScene : public IECoreScene::SampledSceneInterface
 };
 
 } // namespace IECoreAlembic
-
-#endif // IECOREALEMBIC_ALEMBICSCENE_H
diff --git a/contrib/IECoreAlembic/include/IECoreAlembic/Export.h b/contrib/IECoreAlembic/include/IECoreAlembic/Export.h
@@ -33,8 +33,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREALEMBIC_EXPORT_H
-#define IECOREALEMBIC_EXPORT_H
+#pragma once
 
 #include "IECore/Export.h"
 
@@ -46,5 +45,3 @@
 #else
 	#define IECOREALEMBIC_API IECORE_IMPORT
 #endif
-
-#endif // #ifndef IECOREALEMBIC_EXPORT_H
diff --git a/contrib/IECoreAlembic/include/IECoreAlembic/IGeomParamTraits.h b/contrib/IECoreAlembic/include/IECoreAlembic/IGeomParamTraits.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREALEMBIC_IGEOMPARAMTRAITS_H
-#define IECOREALEMBIC_IGEOMPARAMTRAITS_H
+#pragma once
 
 #include "IECore/VectorTypedData.h"
 
@@ -93,5 +92,3 @@ IECOREALEMBIC_SPECIALISEGEOMPARAMTRAITS( Alembic::AbcGeom::IN3dGeomParam, IECore
 IECOREALEMBIC_SPECIALISEGEOMPARAMTRAITS( Alembic::AbcGeom::IBoolGeomParam, IECore::BoolVectorData, IECore::GeometricData::None )
 
 } // namespace IECoreAlembic
-
-#endif // IECOREALEMBIC_IGEOMPARAMTRAITS_H
diff --git a/contrib/IECoreAlembic/include/IECoreAlembic/ObjectReader.h b/contrib/IECoreAlembic/include/IECoreAlembic/ObjectReader.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREALEMBIC_OBJECTREADER_H
-#define IECOREALEMBIC_OBJECTREADER_H
+#pragma once
 
 #include "IECoreAlembic/Export.h"
 
@@ -107,5 +106,3 @@ class ObjectReader : private boost::noncopyable
 };
 
 } // namespace IECoreAlembic
-
-#endif // IECOREALEMBIC_OBJECTREADER_H
diff --git a/contrib/IECoreAlembic/include/IECoreAlembic/ObjectWriter.h b/contrib/IECoreAlembic/include/IECoreAlembic/ObjectWriter.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREALEMBIC_OBJECTWRITER_H
-#define IECOREALEMBIC_OBJECTWRITER_H
+#pragma once
 
 #include "IECoreAlembic/Export.h"
 
@@ -105,4 +104,3 @@ class ObjectWriter : private boost::noncopyable
 
 } // namespace IECoreAlembic
 
-#endif // IECOREALEMBIC_OBJECTWRITER_H
diff --git a/contrib/IECoreAlembic/include/IECoreAlembic/PrimitiveReader.h b/contrib/IECoreAlembic/include/IECoreAlembic/PrimitiveReader.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREALEMBIC_PRIMITIVEREADER_H
-#define IECOREALEMBIC_PRIMITIVEREADER_H
+#pragma once
 
 #include "IECoreAlembic/ObjectReader.h"
 
@@ -67,4 +66,3 @@ class PrimitiveReader : public ObjectReader
 
 #include "IECoreAlembic/PrimitiveReader.inl"
 
-#endif // IECOREALEMBIC_PRIMITIVEREADER_H
diff --git a/contrib/IECoreAlembic/include/IECoreAlembic/PrimitiveReader.inl b/contrib/IECoreAlembic/include/IECoreAlembic/PrimitiveReader.inl
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREALEMBIC_PRIMITIVEREADER_INL
-#define IECOREALEMBIC_PRIMITIVEREADER_INL
+#pragma once
 
 #include "IECoreAlembic/IGeomParamTraits.h"
 
@@ -161,5 +160,3 @@ void PrimitiveReader::readGeomParam( const T &param, const Alembic::Abc::ISample
 }
 
 } // namespace IECoreAlembic
-
-#endif // IECOREALEMBIC_PRIMITIVEREADER_INL
diff --git a/contrib/IECoreAlembic/include/IECoreAlembic/PrimitiveWriter.h b/contrib/IECoreAlembic/include/IECoreAlembic/PrimitiveWriter.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREALEMBIC_PRIMITIVEWRITER_H
-#define IECOREALEMBIC_PRIMITIVEWRITER_H
+#pragma once
 
 #include "IECoreAlembic/ObjectWriter.h"
 
@@ -76,4 +75,3 @@ class PrimitiveWriter : public ObjectWriter
 
 #include "IECoreAlembic/PrimitiveWriter.inl"
 
-#endif // IECOREALEMBIC_PRIMITIVEWRITER_H
diff --git a/contrib/IECoreAlembic/include/IECoreAlembic/PrimitiveWriter.inl b/contrib/IECoreAlembic/include/IECoreAlembic/PrimitiveWriter.inl
@@ -33,8 +33,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREALEMBIC_PRIMITIVEWRITER_INL
-#define IECOREALEMBIC_PRIMITIVEWRITER_INL
+#pragma once
 
 namespace IECoreAlembic
 {
@@ -65,5 +64,3 @@ typename GeomParamType::Sample PrimitiveWriter::geomParamSample( const IECoreSce
 }
 
 } // namespace IECoreAlembic
-
-#endif // IECOREALEMBIC_PRIMITIVEWRITER_INL
diff --git a/contrib/IECoreAlembic/include/IECoreAlembic/TypeIds.h b/contrib/IECoreAlembic/include/IECoreAlembic/TypeIds.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREALEMBIC_TYPEIDS_H
-#define IECOREALEMBIC_TYPEIDS_H
+#pragma once
 
 namespace IECoreAlembic
 {
@@ -46,4 +45,3 @@ enum TypeId
 
 } // namespace IECoreAlembic
 
-#endif // IECOREALEMBIC_TYPEIDS_H
diff --git a/contrib/IECoreUSD/include/IECoreUSD/AttributeAlgo.h b/contrib/IECoreUSD/include/IECoreUSD/AttributeAlgo.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREUSD_ATTRIBUTEALGO_H
-#define IECOREUSD_ATTRIBUTEALGO_H
+#pragma once
 
 #include "IECoreUSD/Export.h"
 
@@ -85,4 +84,3 @@ IECOREUSD_API pxr::TfToken cortexPrimitiveVariableMetadataTokenDeprecated();
 
 } // namespace IECoreUSD
 
-#endif // IECOREUSD_ATTRIBUTEALGO_H
diff --git a/contrib/IECoreUSD/include/IECoreUSD/DataAlgo.h b/contrib/IECoreUSD/include/IECoreUSD/DataAlgo.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREUSD_DATAALGO_H
-#define IECOREUSD_DATAALGO_H
+#pragma once
 
 #include "IECoreUSD/Export.h"
 #include "IECoreUSD/TypeTraits.h"
@@ -108,4 +107,3 @@ IECOREUSD_API pxr::TfToken role( IECore::GeometricData::Interpretation interpret
 
 #include "IECoreUSD/DataAlgo.inl"
 
-#endif // IECOREUSD_DATAALGO_H
diff --git a/contrib/IECoreUSD/include/IECoreUSD/DataAlgo.inl b/contrib/IECoreUSD/include/IECoreUSD/DataAlgo.inl
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREUSD_DATAALGO_INL
-#define IECOREUSD_DATAALGO_INL
+#pragma once
 
 IECORE_PUSH_DEFAULT_VISIBILITY
 #include "pxr/base/gf/quatf.h"
@@ -156,5 +155,3 @@ typename CortexTypeTraits<T>::USDType toUSD( const T &value, typename std::enabl
 } // namespace DataAlgo
 
 } // namespace IECoreUSD
-
-#endif // IECOREUSD_DATAALGO_INL
diff --git a/contrib/IECoreUSD/include/IECoreUSD/Export.h b/contrib/IECoreUSD/include/IECoreUSD/Export.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREUSD_EXPORT_H
-#define IECOREUSD_EXPORT_H
+#pragma once
 
 #include "IECore/Export.h"
 
@@ -42,5 +41,3 @@
 #else
 	#define IECOREUSD_API IECORE_IMPORT
 #endif
-
-#endif // #ifndef IECOREUSD_EXPORT_H
diff --git a/contrib/IECoreUSD/include/IECoreUSD/ObjectAlgo.h b/contrib/IECoreUSD/include/IECoreUSD/ObjectAlgo.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREUSD_OBJECTALGO_H
-#define IECOREUSD_OBJECTALGO_H
+#pragma once
 
 #include "IECoreUSD/Export.h"
 
@@ -132,4 +131,3 @@ struct WriterDescription
 
 } // namespace IECoreUSD
 
-#endif // IECOREUSD_OBJECTALGO_H
diff --git a/contrib/IECoreUSD/include/IECoreUSD/PrimitiveAlgo.h b/contrib/IECoreUSD/include/IECoreUSD/PrimitiveAlgo.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREUSD_PRIMITIVEALGO_H
-#define IECOREUSD_PRIMITIVEALGO_H
+#pragma once
 
 #include "IECoreUSD/Export.h"
 
@@ -89,4 +88,3 @@ IECOREUSD_API IECoreScene::PrimitiveVariable::Interpolation fromUSD( pxr::TfToke
 
 } // namespace IECoreUSD
 
-#endif // IECOREUSD_PRIMITIVEALGO_H
diff --git a/contrib/IECoreUSD/include/IECoreUSD/SceneCacheDataAlgo.h b/contrib/IECoreUSD/include/IECoreUSD/SceneCacheDataAlgo.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREUSD_SCENECACHEDATAALGO_H
-#define IECOREUSD_SCENECACHEDATAALGO_H
+#pragma once
 
 #include "IECoreUSD/Export.h"
 
@@ -65,4 +64,3 @@ IECOREUSD_API std::string toInternalName( const IECore::InternedString& name );
 } // namespace IECoreUSD
 
 
-#endif // IECOREUSD_SCENECACHEDATAALGO_H
diff --git a/contrib/IECoreUSD/include/IECoreUSD/ShaderAlgo.h b/contrib/IECoreUSD/include/IECoreUSD/ShaderAlgo.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREUSD_SHADERALGO_H
-#define IECOREUSD_SHADERALGO_H
+#pragma once
 
 #include "IECoreUSD/Export.h"
 
@@ -72,4 +71,3 @@ IECOREUSD_API bool lightMightBeTimeVarying( const pxr::UsdLuxLightAPI &light );
 
 } // namespace IECoreUSD
 
-#endif // IECOREUSD_SHADERALGO_H
diff --git a/contrib/IECoreUSD/include/IECoreUSD/TypeTraits.h b/contrib/IECoreUSD/include/IECoreUSD/TypeTraits.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREUSD_TYPETRAITS_H
-#define IECOREUSD_TYPETRAITS_H
+#pragma once
 
 #include "IECore/GeometricTypedData.h"
 #include "IECore/InternedString.h"
@@ -125,4 +124,3 @@ IECOREUSD_USDTYPETRAITS_SPECIALISATION( Imath::Quatf, pxr::GfQuath, false, IECor
 
 } // namespace IECoreUSD
 
-#endif // IECOREUSD_TYPETRAITS_H
diff --git a/contrib/IECoreUSD/src/IECoreUSD/SceneCacheData.h b/contrib/IECoreUSD/src/IECoreUSD/SceneCacheData.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREUSD_SCENE_CACHE_DATA_H
-#define IECOREUSD_SCENE_CACHE_DATA_H
+#pragma once
 
 #include "IECoreScene/SceneInterface.h"
 #include "IECoreScene/SharedSceneInterfaces.h"
@@ -188,5 +187,4 @@ class SceneCacheData : public SdfAbstractData
 
 PXR_NAMESPACE_CLOSE_SCOPE
 
-#endif // IECOREUSD_SCENE_CACHE_DATA_H
 
diff --git a/contrib/IECoreUSD/src/IECoreUSD/SceneCacheFileFormat.h b/contrib/IECoreUSD/src/IECoreUSD/SceneCacheFileFormat.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREUSD_SCENECACHEFILEFORMAT_H
-#define IECOREUSD_SCENECACHEFILEFORMAT_H
+#pragma once
 
 #include "USDScene.h"
 
@@ -113,5 +112,4 @@ class UsdSceneCacheFileFormat : public SdfFileFormat
 };
 
 PXR_NAMESPACE_CLOSE_SCOPE
-#endif // IECOREUSD_SCENECACHEFILEFORMAT_H
 
diff --git a/contrib/IECoreUSD/src/IECoreUSD/SdfFileFormatSharedSceneWriters.h b/contrib/IECoreUSD/src/IECoreUSD/SdfFileFormatSharedSceneWriters.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREUSD_SDFFILEFORMATSHAREDSCENEWRITERS_H
-#define IECOREUSD_SDFFILEFORMATSHAREDSCENEWRITERS_H
+#pragma once
 
 #include "IECoreScene/SceneInterface.h"
 
@@ -69,5 +68,4 @@ class SdfFileFormatSharedSceneWriters
 
 } // namespace IECoreUSD
 
-#endif // IECOREUSD_SDFFILEFORMATSHAREDSCENEWRITERS_H
 
diff --git a/contrib/IECoreUSD/src/IECoreUSD/TypeIds.h b/contrib/IECoreUSD/src/IECoreUSD/TypeIds.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREUSD_TYPEIDS_H
-#define IECOREUSD_TYPEIDS_H
+#pragma once
 
 namespace IECoreUSD
 {
@@ -46,4 +45,3 @@ enum TypeId
 
 } // namespace IECoreUSD
 
-#endif // IECOREUSD_TYPEIDS_H
diff --git a/contrib/IECoreUSD/src/IECoreUSD/USDScene.h b/contrib/IECoreUSD/src/IECoreUSD/USDScene.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREUSD_USDSCENE_H
-#define IECOREUSD_USDSCENE_H
+#pragma once
 
 #include "TypeIds.h"
 
@@ -133,4 +132,3 @@ IE_CORE_DECLAREPTR( USDScene )
 
 }
 
-#endif // IECOREUSD_USDSCENE_H
diff --git a/glsl/IECoreGL/ColorAlgo.h b/glsl/IECoreGL/ColorAlgo.h
@@ -32,8 +32,7 @@
 //
 //////////////////////////////////////////////////////////////////////////
 
-#ifndef IECOREGL_COLORALGO_H
-#define IECOREGL_COLORALGO_H
+#pragma once
 
 float ieLuminance( vec3 color, vec3 weights )
 {
@@ -164,4 +163,3 @@ vec3 ieRgbToHSV( vec3 rgb )
 	return result;
 }
 
-#endif // IECOREGL_COLORALGO_H