adobe · jakes-adobe · Jan 31, 2025 · Jan 31, 2025 · Jan 31, 2025
diff --git a/.gitignore b/.gitignore
@@ -53,4 +53,7 @@ test/assets/fbx/*.usd
 test/assets/gltf/*.usd
 test/assets/obj/*/*.usd
 test/assets/ply/*.usd
-test/assets/stl/*.usd
+test/assets/stl/*.usd
+
+# Other
+.DS_Store
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -37,10 +37,12 @@ option(USD_FILEFORMATS_FETCH_DRACO "Forces FetchContent for Draco" OFF)
 option(USD_FILEFORMATS_FETCH_ZLIB "Forces FetchContent for Zlib" OFF)
 option(USD_FILEFORMATS_FETCH_LIBXML2 "Forces FetchContent for LibXml2" ON)
 option(USD_FILEFORMATS_FETCH_HAPPLY "Forces FetchContent for Happly" ON)
+option(USD_FILEFORMATS_FETCH_SPHERICAL_HARMONICS "Forces FetchContent for SphericalHarmonics" ON)
 option(USD_FILEFORMATS_FETCH_FMT "Forces FetchContent for Fmt" ON)
 option(USD_FILEFORMATS_FETCH_FASTFLOAT "Forces FetchContent for FastFLoat" ON)
 option(USD_FILEFORMATS_ENABLE_CXX11_ABI "Use the CXX 11 ABI on Linux" OFF)
 option(USD_FILEFORMATS_ENABLE_ASM  "Enables ASM material representation"   OFF)
+option(USD_FILEFORMATS_FETCH_SPHERICAL_HARMONICS "Forces FetchContent for SphericalHarmonics" ON)
 
 # This is a future looking option which turns on/off writing MaterialX Shaders
 # when importing a file per the OpenPBR spec:

diff --git a/README.md b/README.md
@@ -1,6 +1,6 @@
 [![](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/kwblackstone/264643f3d2acacc5369a0ba70854dfb6/raw/windows-2022-2411-ALL.json)](https://github.com/adobe/USD-Fileformat-plugins/actions/workflows/ci.yml) [![](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/kwblackstone/264643f3d2acacc5369a0ba70854dfb6/raw/windows-2022-2408-ALL.json)](https://github.com/adobe/USD-Fileformat-plugins/actions/workflows/ci.yml) [![](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/kwblackstone/264643f3d2acacc5369a0ba70854dfb6/raw/windows-2022-2311-ALL.json)](https://github.com/adobe/USD-Fileformat-plugins/actions/workflows/ci.yml) [![](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/kwblackstone/264643f3d2acacc5369a0ba70854dfb6/raw/windows-2022-2308-ALL.json)](https://github.com/adobe/USD-Fileformat-plugins/actions/workflows/ci.yml)
 
-[![](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/kwblackstone/264643f3d2acacc5369a0ba70854dfb6/raw/macOS-14-2411-ALL.json)](https://github.com/adobe/USD-Fileformat-plugins/actions/workflows/ci.yml) [![](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/kwblackstone/264643f3d2acacc5369a0ba70854dfb6/raw/macOS-14-2408-ALL.json)](https://github.com/adobe/USD-Fileformat-plugins/actions/workflows/ci.yml) [![](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/kwblackstone/264643f3d2acacc5369a0ba70854dfb6/raw/macOS-14-2411-ALL.json)](https://github.com/adobe/USD-Fileformat-plugins/actions/workflows/ci.yml)
+[![](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/kwblackstone/264643f3d2acacc5369a0ba70854dfb6/raw/macOS-14-2411-ALL.json)](https://github.com/adobe/USD-Fileformat-plugins/actions/workflows/ci.yml) [![](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/kwblackstone/264643f3d2acacc5369a0ba70854dfb6/raw/macOS-14-2408-ALL.json)](https://github.com/adobe/USD-Fileformat-plugins/actions/workflows/ci.yml) [![](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/kwblackstone/264643f3d2acacc5369a0ba70854dfb6/raw/macOS-14-2405-ALL.json)](https://github.com/adobe/USD-Fileformat-plugins/actions/workflows/ci.yml)
 
 [![](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/kwblackstone/264643f3d2acacc5369a0ba70854dfb6/raw/macOS-13-2411-ALL.json)](https://github.com/adobe/USD-Fileformat-plugins/actions/workflows/ci.yml) [![](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/kwblackstone/264643f3d2acacc5369a0ba70854dfb6/raw/macOS-13-2408-ALL.json)](https://github.com/adobe/USD-Fileformat-plugins/actions/workflows/ci.yml)[![](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/kwblackstone/264643f3d2acacc5369a0ba70854dfb6/raw/macOS-13-2405-ALL.json)](https://github.com/adobe/USD-Fileformat-plugins/actions/workflows/ci.yml) [![](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/kwblackstone/264643f3d2acacc5369a0ba70854dfb6/raw/macOS-13-2311-ALL.json)](https://github.com/adobe/USD-Fileformat-plugins/actions/workflows/ci.yml) [![](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/kwblackstone/264643f3d2acacc5369a0ba70854dfb6/raw/macOS-13-2308-ALL.json)](https://github.com/adobe/USD-Fileformat-plugins/actions/workflows/ci.yml)
 
@@ -41,17 +41,19 @@ The following tools are needed:
 The following dependencies are needed:
 |Dependency|Version|Affects|Optional|
 |--|--|--|--|
-| [Pixar USD](https://github.com/PixarAnimationStudios/USD)         | 23.08       | all       | no  |
-| [GTest](https://github.com/google/googletest.git)                 | 1.11.0      | all tests | yes |
-| [FBX SDK](https://aps.autodesk.com/developer/overview/fbx-sdk)    | 2020.3.7    | usdfbx    | no  |
-| [LibXml2](https://gitlab.gnome.org/GNOME/libxml2)                 | 2.10.0      | usdfbx    | no  |
-| [Zlib](https://github.com/madler/zlib.git)                        | 1.2.11      | usdfbx    | no  |
-| [TinyGltf](https://github.com/syoyo/tinygltf)                     | 2.8.21      | usdgltf   | no  |
-| [Draco](https://github.com/google/draco.git)                      | 1.56        | usdgltf   | yes |
-| [Fmt](https://github.com/fmtlib/fmt.git)                          | 10.1.1      | usdobj    | no  |
-| [FastFloat](https://github.com/lemire/fast_float.git)             | 1.1.2       | usdobj    | no  |
-| [Happly](https://github.com/nmwsharp/happly.git)                  | cfa2611     | usdply    | no |
-| [Substance](https://developer.adobe.com/substance3d-sdk/)         | 9.1.2       | usdsbsar  | no |
+| [Pixar USD](https://github.com/PixarAnimationStudios/USD)            | 23.08       | all       | no  |
+| [GTest](https://github.com/google/googletest.git)                    | 1.11.0      | all tests | yes |
+| [Eigen](https://gitlab.com/libeigen/eigen)                           | 3.4.0       | usdply    | no  |
+| [FBX SDK](https://aps.autodesk.com/developer/overview/fbx-sdk)       | 2020.3.7    | usdfbx    | no  |
+| [LibXml2](https://gitlab.gnome.org/GNOME/libxml2)                    | 2.10.0      | usdfbx    | no  |
+| [Zlib](https://github.com/madler/zlib.git)                           | 1.2.11      | usdfbx    | no  |
+| [TinyGltf](https://github.com/syoyo/tinygltf)                        | 2.8.21      | usdgltf   | no  |
+| [Draco](https://github.com/google/draco.git)                         | 1.56        | usdgltf   | yes |
+| [Fmt](https://github.com/fmtlib/fmt.git)                             | 10.1.1      | usdobj    | no  |
+| [FastFloat](https://github.com/lemire/fast_float.git)                | 1.1.2       | usdobj    | no  |
+| [Happly](https://github.com/nmwsharp/happly.git)                     | cfa2611     | usdply    | no  |
+| [Spherical Harmonics](https://github.com/google/spherical-harmonics) | ccb6c7f     | usdply    | no  |
+| [Substance](https://developer.adobe.com/substance3d-sdk/)            | 9.1.2       | usdsbsar  | no  |
 
 ## Build
 
@@ -141,8 +143,6 @@ where:
 | -DUSD_FILEFORMATS_FETCH_FASTFLOAT | Forces FetchContent for FastFLoat | ON | usdobj |
 | -DUSD_FILEFORMATS_ENABLE_ASM | Generate a ASM based material network on layerwrite | OFF |
 
-Note that `Dpxr_ROOT` is *not* an optional parameter - a reference to the OpenUSD installation path **has** to be passed.
-
 ZLIB, Draco and OpenImageIO packages are hinted to search into the USD installation by default. Override this by setting their ROOT or their FETCH variables (no fetch for OIIO).
 
 The previous commands will place intermediate files into the folder `build` and install binaries into the folder `bin`.
@@ -157,7 +157,7 @@ Also, make the plugins discoverable by USD to complete installation, by adding t
   ```bash
   python ./USD/build_scripts/build_usd.py ./usd-install  --build-shared --usd-imaging --tools --generator <GENERATOR> --openimageio --build-variant release
   ```
-  #### For Linux/Mac:
+  #### For Linux:
   ```bash
   python ./USD/build_scripts/build_usd.py ./usd-install  --use-cxx11-abi=1 --build-shared --usd-imaging --tools --generator <GENERATOR> --openimageio --build-variant release
   ```
@@ -175,12 +175,19 @@ Environment Variables
   set PATH=%PATH%;.\USD-Fileformat-plugins\bin\bin;.\USD-Fileformat-plugins\bin\plugin\usd
   set PXR_PLUGINPATH_NAME=%PXR_PLUGINPATH_NAME%;.\USD-Fileformat-plugins\bin\plugin\usd
   ```
-#### For Linux/Mac
+#### For Linux
   ```bash
   export PATH=$PATH:./USD-Fileformat-plugins/bin/bin:./USD-Fileformat-plugins/bin/plugin/usd
   export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:./USD-Fileformat-plugins/bin/lib:./USD-Fileformat-plugins/bin/lib64
   export PXR_PLUGINPATH_NAME=$PXR_PLUGINPATH_NAME:./USD-Fileformat-plugins/bin/plugin/usd
   ```
+#### For Mac
+  ```bash
+  export PATH=$PATH:./USD-Fileformat-plugins/bin/bin:./USD-Fileformat-plugins/bin/plugin/usd
+  export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:./USD-Fileformat-plugins/bin/lib
+  export DYLD_LIBRARY_PATH=$DYLD_LIBRARY_PATH:./USD-Fileformat-plugins/bin/lib
+  export PXR_PLUGINPATH_NAME=$PXR_PLUGINPATH_NAME:./USD-Fileformat-plugins/bin/plugin/usd
+  ```
 
 Or Copy plugins:
 * Copy the installed plugins and dependent shared libraries to the specified folder:
@@ -259,4 +266,4 @@ To generate the documentation go to the project root folder and enter:
 ```
 doxygen
 ```
-The resulting documentation will be placed at the `docs` folder.
+The resulting documentation will be placed at the `docs` folder.
diff --git a/changelog.txt b/changelog.txt
@@ -1,3 +1,30 @@
+v1.1.0  January 31st, 2025
+fbx:
+    - add display name to USD to save imported names for export
+    - import specular roughness from autodesk standard surface
+    - interpolate diffuse color on export for intermediate metallic values
+    - avoid creating extra root nodes during import & export
+    - adjust mesh and mesh instancing setup
+gltf:
+    - add display name to USD to save imported names for export
+    - ignore invalid indices on export
+    - adjust mesh and mesh instancing setup
+ply:
+    - add spherical harmonics support
+    - detect nan values for gsplat opacity and convert to 0
+    - fix for loading ply files with non-ascii characters in filename
+sbsar
+    - updated the list of sbsar engines for mac x64 to include metal
+    - add emissive intensity of 1 when we find emissive color
+    - set scale and bias correctly for normal map reader nodes
+utility:
+    - update required env vars for Mac in Readme
+    - print OIIO error on failure
+    - restrict XForm collapsing to DefaultPrim
+    - usd v24.11 cleanup
+    - refactor utility exporting, cmake cleanup, rename files, remove extra logs
+
+
 v1.0.10  November 19th, 2024
 fbx:
     - small fbx spot light fixes

diff --git a/cmake/CPM.cmake b/cmake/CPM.cmake
@@ -0,0 +1,33 @@
+set(CPM_DOWNLOAD_VERSION 0.40.2)
+
+if(CPM_SOURCE_CACHE)
+  set(CPM_DOWNLOAD_LOCATION "${CPM_SOURCE_CACHE}/cpm/CPM_${CPM_DOWNLOAD_VERSION}.cmake")
+elseif(DEFINED ENV{CPM_SOURCE_CACHE})
+  set(CPM_DOWNLOAD_LOCATION "$ENV{CPM_SOURCE_CACHE}/cpm/CPM_${CPM_DOWNLOAD_VERSION}.cmake")
+else()
+  set(CPM_DOWNLOAD_LOCATION "${CMAKE_BINARY_DIR}/cmake/CPM_${CPM_DOWNLOAD_VERSION}.cmake")
+endif()
+
+# Expand relative path. This is important if the provided path contains a tilde (~)
+get_filename_component(CPM_DOWNLOAD_LOCATION ${CPM_DOWNLOAD_LOCATION} ABSOLUTE)
+
+function(download_cpm)
+  message(STATUS "Downloading CPM.cmake to ${CPM_DOWNLOAD_LOCATION}")
+  file(DOWNLOAD
+       https://github.com/cpm-cmake/CPM.cmake/releases/download/v${CPM_DOWNLOAD_VERSION}/CPM.cmake
+       ${CPM_DOWNLOAD_LOCATION}
+  )
+endfunction()
+
+if(NOT (EXISTS ${CPM_DOWNLOAD_LOCATION}))
+  download_cpm()
+else()
+  # resume download if it previously failed
+  file(READ ${CPM_DOWNLOAD_LOCATION} check)
+  if("${check}" STREQUAL "")
+    download_cpm()
+  endif()
+  unset(check)
+endif()
+
+include(${CPM_DOWNLOAD_LOCATION})
diff --git a/cmake/FindEigen3.cmake b/cmake/FindEigen3.cmake
@@ -0,0 +1,63 @@
+if(TARGET Eigen3::Eigen)
+    return()
+endif()
+
+option(EIGEN_WITH_MKL "Use Eigen with MKL" OFF)
+option(EIGEN_DONT_VECTORIZE "Disable Eigen vectorization" OFF)
+
+if(EIGEN_ROOT)
+    message(STATUS "Third-party (external): creating target 'Eigen3::Eigen' for external path: ${EIGEN_ROOT}")
+    set(EIGEN_INCLUDE_DIRS ${EIGEN_ROOT})
+else()
+    message(STATUS "Third-party (external): creating target 'Eigen3::Eigen'")
+
+    include(CPM)
+    CPMAddPackage(
+        NAME eigen
+        GIT_REPOSITORY https://gitlab.com/libeigen/eigen.git
+        GIT_TAG 3.4.0
+        DOWNLOAD_ONLY ON
+    )
+    set(EIGEN_INCLUDE_DIRS ${eigen_SOURCE_DIR})
+
+    install(DIRECTORY ${EIGEN_INCLUDE_DIRS}/Eigen
+        DESTINATION include
+    )
+endif()
+
+add_library(Eigen3_Eigen INTERFACE)
+add_library(Eigen3::Eigen ALIAS Eigen3_Eigen)
+
+include(GNUInstallDirs)
+target_include_directories(Eigen3_Eigen SYSTEM INTERFACE
+    $<BUILD_INTERFACE:${EIGEN_INCLUDE_DIRS}>
+    $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
+)
+target_compile_definitions(Eigen3_Eigen INTERFACE EIGEN_MPL2_ONLY)
+
+if(EIGEN_DONT_VECTORIZE)
+    target_compile_definitions(Eigen3_Eigen INTERFACE EIGEN_DONT_VECTORIZE)
+endif()
+
+if(EIGEN_WITH_MKL)
+    # TODO: Checks that, on 64bits systems, `mkl::mkl` is using the LP64 interface
+    # (by looking at the compile definition of the target)
+    include(mkl)
+    target_link_libraries(Eigen3_Eigen INTERFACE mkl::mkl)
+    target_compile_definitions(Eigen3_Eigen INTERFACE
+        EIGEN_USE_MKL_ALL
+        EIGEN_USE_LAPACKE_STRICT
+    )
+endif()
+
+# On Windows, enable natvis files to improve debugging experience
+if(WIN32 AND eigen_SOURCE_DIR)
+    target_sources(Eigen3_Eigen INTERFACE $<BUILD_INTERFACE:${eigen_SOURCE_DIR}/debug/msvc/eigen.natvis>)
+endif()
+
+# Install rules
+set(CMAKE_INSTALL_DEFAULT_COMPONENT_NAME eigen)
+set_target_properties(Eigen3_Eigen PROPERTIES EXPORT_NAME Eigen)
+install(DIRECTORY ${EIGEN_INCLUDE_DIRS} DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+install(TARGETS Eigen3_Eigen EXPORT Eigen_Targets)
+install(EXPORT Eigen_Targets DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/eigen NAMESPACE Eigen3::)
diff --git a/cmake/FindSphericalHarmonics.cmake b/cmake/FindSphericalHarmonics.cmake
@@ -0,0 +1,100 @@
+#[=======================================================================[.rst:
+----
+
+Finds or fetches the spherical-harmonics library.
+If USD_FILEFORMATS_FORCE_FETCHCONTENT or USD_FILEFORMATS_FETCH_SPHERICAL_HARMONICS are 
+TRUE, spherical-harmonics will be fetched. Otherwise it will be searched via find commands.
+
+Imported Targets
+^^^^^^^^^^^^^^^^
+
+This module provides the following imported targets, if fetched:
+
+``SphericalHarmonics::SphericalHarmonics``
+  The SphericalHarmonics library
+
+Result Variables
+^^^^^^^^^^^^^^^^
+
+This will define the following variables:
+
+``SphericalHarmonics_FOUND``
+
+Cache Variables
+^^^^^^^^^^^^^^^
+
+The following cache variables may also be set:
+
+``SH_INCLUDE_DIR``
+  The directory containing ``sh/spherical_harmonics.h``.
+
+#]=======================================================================]
+
+if(TARGET SphericalHarmonics::SphericalHarmonics)
+    return()
+endif()
+
+if (NOT TARGET Eigen3::Eigen)
+    find_package(Eigen3 REQUIRED)
+endif()
+
+if(USD_FILEFORMATS_FORCE_FETCHCONTENT OR USD_FILEFORMATS_FETCH_SPHERICAL_HARMONICS)
+    message(STATUS "Fetching SphericalHarmonics")
+    include(FetchContent)
+    FetchContent_Declare(
+        spherical_harmonics_git
+        GIT_REPOSITORY "https://github.com/google/spherical-harmonics.git"
+        GIT_TAG        "ccb6c7fec875a1cd5ce5eb1315a9fa7603e0919a"
+    )
+    FetchContent_MakeAvailable(spherical_harmonics_git)
+
+    if(spherical_harmonics_git_POPULATED)
+        set(SphericalHarmonics_FOUND TRUE)
+        set(SH_SRC_FILES
+            ${spherical_harmonics_git_SOURCE_DIR}/sh/spherical_harmonics.cc
+            ${spherical_harmonics_git_SOURCE_DIR}/sh/spherical_harmonics.h
+            ${spherical_harmonics_git_SOURCE_DIR}/sh/image.h
+        )
+        add_library(SphericalHarmonics STATIC)
+        target_sources(SphericalHarmonics PRIVATE ${SH_SRC_FILES})
+        set(SH_INCLUDE_DIR "${spherical_harmonics_git_SOURCE_DIR}")
+        target_include_directories(SphericalHarmonics PUBLIC ${SH_INCLUDE_DIR})
+        target_link_libraries(SphericalHarmonics PUBLIC Eigen3::Eigen)
+        set_property(TARGET SphericalHarmonics PROPERTY POSITION_INDEPENDENT_CODE ON)
+        set_property(TARGET SphericalHarmonics PROPERTY CXX_STANDARD 17)
+        target_compile_definitions(SphericalHarmonics PRIVATE "_USE_MATH_DEFINES")
+        add_library(SphericalHarmonics::SphericalHarmonics ALIAS SphericalHarmonics)
+    endif()
+else()
+    include(FindPackageHandleStandardArgs)
+
+    find_path(SH_INCLUDE_DIR
+        NAMES sh/spherical_harmonics.h
+    )
+
+    find_package_handle_standard_args(SphericalHarmonics
+        REQUIRED_VARS SH_INCLUDE_DIR
+    )
+
+    if(SphericalHarmonics_FOUND)
+        set(SH_SRC_FILES
+            ${SH_INCLUDE_DIR}/sh/spherical_harmonics.cc
+            ${SH_INCLUDE_DIR}/sh/spherical_harmonics.h
+            ${SH_INCLUDE_DIR}/sh/image.h
+        )
+        add_library(SphericalHarmonics STATIC)
+        target_sources(SphericalHarmonics PRIVATE ${SH_SRC_FILES})
+        set(SH_INCLUDE_DIR "${SphericalHarmonics_SOURCE_DIR}")
+        target_include_directories(SphericalHarmonics PUBLIC ${SH_INCLUDE_DIR})
+        target_link_libraries(SphericalHarmonics PUBLIC Eigen3::Eigen)
+        set_property(TARGET SphericalHarmonics PROPERTY POSITION_INDEPENDENT_CODE ON)
+        set_property(TARGET SphericalHarmonics PROPERTY CXX_STANDARD 17)
+        target_compile_definitions(SphericalHarmonics PRIVATE "_USE_MATH_DEFINES")
+
+       add_library(SphericalHarmonics::SphericalHarmonics ALIAS SphericalHarmonics)
+    elseif(${SphericalHarmonics_FIND_REQUIRED})
+        message(FATAL_ERROR "Could not find SphericalHarmonics")
+    endif()
+endif()
+
+
diff --git a/fbx/README.md b/fbx/README.md
@@ -38,7 +38,7 @@
 |Skeletons                |✅|✅|
 |Skeleton Animations      |✅|⚠️|
 ||||
-|Materials                |✅|✅|
+|Materials                |✅|⚠️|
 
 
 
@@ -74,6 +74,8 @@ opacity → phongSurface::TransparentColor
 ior → Not been used.
 displacement → phongSurface::DisplacementColor
 
+Note that PBR materials are not supported on export, only Phong
+
 - Only point, directional, and spot lights are imported. Other light types are exported as point lights.
 
 - **OBS: The image files used by the UsdPreviewShader node will be extracted from the USDZ file and saved as PNG files in the same folder as the generated fbx. If the source file is USD the files should also be copied from the USD folder into the FBX folder.**

diff --git a/fbx/src/fbx.cpp b/fbx/src/fbx.cpp
@@ -12,7 +12,7 @@ governing permissions and limitations under the License.
 #include "fbx.h"
 #include "debugCodes.h"
 #include <algorithm>
-#include <common.h>
+#include <fileformatutils/common.h>
 #include <fbxsdk.h>
 #include <fstream>
 #include <pxr/base/gf/matrix3d.h>

diff --git a/fbx/src/fbx.h b/fbx/src/fbx.h
@@ -16,7 +16,7 @@ governing permissions and limitations under the License.
 #include <pxr/pxr.h>
 #include <sstream>
 #include <string>
-#include <usdData.h>
+#include <fileformatutils/usdData.h>
 #include <utility>