[WIP] Add C++ bindings

4 files changed, 506 insertions, 0 deletions

diff --git a/bindings/cpp/include/serd/detail/Copyable.hpp b/bindings/cpp/include/serd/detail/Copyable.hpp
new file mode 100644
index 00000000..7b1604d7
--- /dev/null
+++ b/bindings/cpp/include/serd/detail/Copyable.hpp
@@ -0,0 +1,236 @@
+/*
+  Copyright 2019-2021 David Robillard <d@drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#ifndef SERD_DETAIL_COPYABLE_HPP
+#define SERD_DETAIL_COPYABLE_HPP
+
+// IWYU pragma: no_include "serd/serd.h"
+
+#include "serd/detail/DynamicWrapper.hpp"
+#include "serd/detail/StaticWrapper.hpp"
+#include "serd/detail/Wrapper.hpp"
+
+#include <cstddef>
+#include <memory>
+#include <type_traits>
+#include <utility>
+
+namespace serd {
+namespace detail {
+
+/**
+   @addtogroup serdpp_detail
+   @{
+*/
+
+/// Copy function for a C object
+template<class T>
+using CopyFunc = T* (*)(const T*);
+
+template<class T, std::remove_const_t<T>* Copy(SerdAllocator*, const T*)>
+typename std::enable_if_t<std::is_const<T>::value, T>*
+copy(const T* ptr)
+{
+  return ptr; // Making a view (const reference), do not copy
+}
+
+template<class T, std::remove_const_t<T>* Copy(SerdAllocator*, const T*)>
+typename std::enable_if_t<!std::is_const<T>::value, T>*
+copy(const T* ptr)
+{
+  return ptr ? Copy(nullptr, ptr) : nullptr; // Making a mutable wrapper, copy
+}
+
+/**
+   Generic wrapper for a "basic" copyable object.
+
+   This wraps objects with simple ownership semantics where a const pointer is
+   never owned, and a mutable pointer is owned.  This has no space overhead
+   compared to a raw pointer since the ownership is encoded in the type.
+*/
+template<class T,
+         Mutable<T>* Copy(SerdAllocator*, const T*),
+         bool        Equals(const T*, const T*),
+         void        Free(Mutable<T>*)>
+class StaticCopyable : public StaticWrapper<T, Free>
+{
+public:
+  using Deleter = StaticDeleter<T, Free>;
+  using Base    = StaticWrapper<T, Free>;
+
+  explicit StaticCopyable(T* ptr)
+    : Base{ptr}
+  {}
+
+  StaticCopyable(const StaticCopyable& wrapper)
+    : Base(copy<T, Copy>(wrapper.cobj()))
+  {}
+
+  template<class U, void UFree(Mutable<U>*)>
+  explicit StaticCopyable(const StaticCopyable<U, Copy, Equals, UFree>& wrapper)
+    : Base(copy<T, Copy>(wrapper.cobj()))
+  {}
+
+  StaticCopyable(StaticCopyable&&) noexcept = default;
+  ~StaticCopyable() noexcept                = default;
+
+  StaticCopyable& operator=(StaticCopyable&&) noexcept = default;
+
+  StaticCopyable& operator=(const StaticCopyable& wrapper)
+  {
+    if (&wrapper != this) {
+      this->_ptr = std::unique_ptr<T, Deleter>(copy<T, Copy>(wrapper.cobj()));
+    }
+    return *this;
+  }
+
+  template<class U>
+  bool operator==(const StaticCopyable<U, Copy, Equals, Free>& wrapper) const
+  {
+    return Equals(this->cobj(), wrapper.cobj());
+  }
+
+  template<class U>
+  bool operator!=(const StaticCopyable<U, Copy, Equals, Free>& wrapper) const
+  {
+    return !operator==(wrapper);
+  }
+};
+
+/**
+   Generic wrapper for a "basic" copyable object.
+
+   This wraps objects with simple ownership semantics where a const pointer is
+   never owned, and a mutable pointer is owned.  This has no space overhead
+   compared to a raw pointer since the ownership is encoded in the type.
+*/
+template<class T,
+         Mutable<T>* Copy(SerdAllocator*, const T*),
+         bool        Equals(const T*, const T*),
+         void        Free(SerdAllocator*, Mutable<T>*)>
+class StaticAllocatedCopyable : public StaticAllocatedWrapper<T, Free>
+{
+public:
+  using Deleter = StaticAllocatedDeleter<T, Free>;
+  using Base    = StaticAllocatedWrapper<T, Free>;
+
+  explicit StaticAllocatedCopyable(T* ptr)
+    : Base{ptr}
+  {}
+
+  StaticAllocatedCopyable(const StaticAllocatedCopyable& wrapper)
+    : Base(copy<T, Copy>(wrapper.cobj()))
+  {}
+
+  template<class U, void UFree(SerdAllocator*, Mutable<U>*)>
+  explicit StaticAllocatedCopyable(
+    const StaticAllocatedCopyable<U, Copy, Equals, UFree>& wrapper)
+    : Base(copy<T, Copy>(wrapper.cobj()))
+  {}
+
+  StaticAllocatedCopyable(StaticAllocatedCopyable&&) noexcept = default;
+  ~StaticAllocatedCopyable() noexcept                         = default;
+
+  StaticAllocatedCopyable& operator=(StaticAllocatedCopyable&&) noexcept =
+    default;
+
+  StaticAllocatedCopyable& operator=(const StaticAllocatedCopyable& wrapper)
+  {
+    if (&wrapper != this) {
+      this->_ptr = std::unique_ptr<T, Deleter>(copy<T, Copy>(wrapper.cobj()));
+    }
+    return *this;
+  }
+
+  template<class U>
+  bool operator==(
+    const StaticAllocatedCopyable<U, Copy, Equals, Free>& wrapper) const
+  {
+    return Equals(this->cobj(), wrapper.cobj());
+  }
+
+  template<class U>
+  bool operator!=(
+    const StaticAllocatedCopyable<U, Copy, Equals, Free>& wrapper) const
+  {
+    return !operator==(wrapper);
+  }
+};
+
+/**
+   Wrapper for a "dynamic" copyable C object.
+
+   This wraps objects that require dynamic tracking of the ownership.
+*/
+template<class T,
+         Mutable<T>* Copy(SerdAllocator*, const T*),
+         bool        Equals(const T*, const T*),
+         void        Free(Mutable<T>*)>
+class DynamicCopyable : public Wrapper<T, DynamicDeleter<T, Free>>
+{
+public:
+  using Deleter = DynamicDeleter<T, Free>;
+  using Base    = Wrapper<T, Deleter>;
+
+  explicit DynamicCopyable(std::unique_ptr<T, Deleter> ptr)
+    : Base{std::move(ptr)}
+  {}
+
+  DynamicCopyable(const DynamicCopyable& wrapper)
+    : Base{Copy(nullptr /* FIXME */, wrapper.cobj()), Ownership::owned}
+  {}
+
+  DynamicCopyable(DynamicCopyable&&) noexcept = default;
+  DynamicCopyable& operator=(DynamicCopyable&&) noexcept = default;
+
+  ~DynamicCopyable() noexcept = default;
+
+  DynamicCopyable& operator=(const DynamicCopyable& wrapper)
+  {
+    if (&wrapper != this) {
+      this->_ptr = std::unique_ptr<T, Deleter>(
+        Copy(nullptr /* FIXME */, wrapper.cobj()), Ownership::owned);
+    }
+
+    return *this;
+  }
+
+  template<class U>
+  bool operator==(const DynamicCopyable<U, Copy, Equals, Free>& wrapper) const
+  {
+    return Equals(this->cobj(), wrapper.cobj());
+  }
+
+  template<class U>
+  bool operator!=(const DynamicCopyable<U, Copy, Equals, Free>& wrapper) const
+  {
+    return !operator==(wrapper);
+  }
+
+protected:
+  explicit DynamicCopyable(std::nullptr_t)
+    : Base(nullptr)
+  {}
+};
+
+/**
+   @}
+*/
+
+} // namespace detail
+} // namespace serd
+
+#endif // SERD_DETAIL_COPYABLE_HPP
diff --git a/bindings/cpp/include/serd/detail/DynamicWrapper.hpp b/bindings/cpp/include/serd/detail/DynamicWrapper.hpp
new file mode 100644
index 00000000..6b3c898a
--- /dev/null
+++ b/bindings/cpp/include/serd/detail/DynamicWrapper.hpp
@@ -0,0 +1,74 @@
+/*
+  Copyright 2019-2021 David Robillard <d@drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#ifndef SERD_DETAIL_DYNAMICWRAPPER_HPP
+#define SERD_DETAIL_DYNAMICWRAPPER_HPP
+
+// IWYU pragma: no_include "serd/serd.h"
+
+#include "serd/detail/Wrapper.hpp"
+
+#include <type_traits>
+
+namespace serd {
+namespace detail {
+
+/**
+   Ownership for `DynamicDeleter`.
+
+   @ingroup serdpp_detail
+*/
+enum class Ownership {
+  owned, ///< This pointer owns the data and must delete it
+  view,  ///< This pointer is just a view and must not delete the data
+};
+
+/**
+   Deleter for a C object that can handle dynamic ownership.
+
+   Unlike StaticDeleter, this can be used to handle non-owned references to
+   mutable objects, at the cost of an extra word for tracking the ownership
+   (since constness in the type can't convey this information).
+
+   @ingroup serdpp_detail
+*/
+template<class T, void Free(Mutable<T>*)>
+struct DynamicDeleter {
+  // NOLINTNEXTLINE(google-explicit-constructor, hicpp-explicit-conversions)
+  DynamicDeleter(const Ownership ownership)
+    : _ownership{ownership}
+  {}
+
+  template<class = std::enable_if<!std::is_const<T>::value>>
+  void operator()(Mutable<T>* const ptr)
+  {
+    if (_ownership == Ownership::owned) {
+      Free(ptr);
+    }
+  }
+
+  template<class = std::enable_if<std::is_const<T>::value>>
+  void operator()(const T*)
+  {}
+
+private:
+  Ownership _ownership;
+};
+
+} // namespace detail
+} // namespace serd
+
+#endif // SERD_DETAIL_DYNAMICWRAPPER_HPP
diff --git a/bindings/cpp/include/serd/detail/StaticWrapper.hpp b/bindings/cpp/include/serd/detail/StaticWrapper.hpp
new file mode 100644
index 00000000..9ca82118
--- /dev/null
+++ b/bindings/cpp/include/serd/detail/StaticWrapper.hpp
@@ -0,0 +1,97 @@
+/*
+  Copyright 2019-2021 David Robillard <d@drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#ifndef SERD_DETAIL_STATICWRAPPER_HPP
+#define SERD_DETAIL_STATICWRAPPER_HPP
+
+// IWYU pragma: no_include "serd/serd.h"
+
+#include "serd/detail/Wrapper.hpp"
+
+#include <type_traits>
+
+namespace serd {
+namespace detail {
+
+/**
+   Simple overhead-free deleter for a C object.
+
+   Can be used with const or mutable pointers, but only mutable pointers will
+   be freed.  In other words, mutability implies ownership, and this can not
+   handle unowned mutable pointers.
+
+   @ingroup serdpp_detail
+*/
+template<class T, void Free(Mutable<T>*)>
+struct StaticDeleter {
+  template<class = std::enable_if<!std::is_const<T>::value>>
+  void operator()(Mutable<T>* const ptr)
+  {
+    Free(ptr);
+  }
+
+  template<class = std::enable_if<std::is_const<T>::value>>
+  void operator()(const T*)
+  {}
+};
+
+/// Simple overhead-free wrapper for a C object that can free itself
+template<class T, void Free(std::remove_const_t<T>*)>
+class StaticWrapper : public Wrapper<T, StaticDeleter<T, Free>>
+{
+public:
+  explicit StaticWrapper(T* const ptr)
+    : Wrapper<T, StaticDeleter<T, Free>>{ptr}
+  {}
+};
+
+/**
+   Simple overhead-free deleter for a C object.
+
+   Can be used with const or mutable pointers, but only mutable pointers will
+   be freed.  In other words, mutability implies ownership, and this can not
+   handle unowned mutable pointers.
+
+   @ingroup serdpp_detail
+*/
+template<class T, void Free(SerdAllocator*, Mutable<T>*)>
+struct StaticAllocatedDeleter {
+  template<class = std::enable_if<!std::is_const<T>::value>>
+  void operator()(Mutable<T>* const ptr)
+  {
+    Free(nullptr, ptr);
+  }
+
+  template<class = std::enable_if<std::is_const<T>::value>>
+  void operator()(const T*)
+  {}
+};
+
+/// Simple overhead-free wrapper for a C object that uses an allocator
+template<class T, void Free(SerdAllocator*, std::remove_const_t<T>*)>
+class StaticAllocatedWrapper
+  : public Wrapper<T, StaticAllocatedDeleter<T, Free>>
+{
+public:
+  explicit StaticAllocatedWrapper(T* const ptr)
+    : Wrapper<T, StaticAllocatedDeleter<T, Free>>{ptr}
+  {}
+};
+
+} // namespace detail
+} // namespace serd
+
+#endif // SERD_DETAIL_STATICWRAPPER_HPP
diff --git a/bindings/cpp/include/serd/detail/Wrapper.hpp b/bindings/cpp/include/serd/detail/Wrapper.hpp
new file mode 100644
index 00000000..39426775
--- /dev/null
+++ b/bindings/cpp/include/serd/detail/Wrapper.hpp
@@ -0,0 +1,99 @@
+/*
+  Copyright 2019-2021 David Robillard <d@drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#ifndef SERD_DETAIL_WRAPPER_HPP
+#define SERD_DETAIL_WRAPPER_HPP
+
+// IWYU pragma: no_include "serd/serd.h"
+
+#include <cstddef>
+#include <memory>
+#include <type_traits>
+#include <utility>
+
+namespace serd {
+
+/// Utility template for a mutable type which removes const if necessary
+template<class T>
+class Optional;
+
+/// Detail namespace
+namespace detail {
+
+/**
+   @defgroup serdpp_detail Serd C++ API details
+   Internal C++ wrapper details that should not be used directly by clients.
+   @ingroup serdpp
+   @{
+*/
+
+/// Utility template for a mutable type which removes const if necessary
+template<class T>
+using Mutable = typename std::remove_const_t<T>;
+
+/// Generic C++ wrapper for a C object
+template<class T, class Deleter>
+class Wrapper
+{
+public:
+  using CType = T;
+
+  explicit Wrapper(T* ptr)
+    : _ptr{ptr, Deleter{}}
+  {}
+
+  Wrapper(T* ptr, Deleter deleter)
+    : _ptr{ptr, std::move(deleter)}
+  {}
+
+  explicit Wrapper(std::unique_ptr<T, Deleter> ptr)
+    : _ptr{std::move(ptr)}
+  {}
+
+  Wrapper(Wrapper&&) noexcept = default;
+  Wrapper& operator=(Wrapper&&) noexcept = default;
+
+  Wrapper(const Wrapper&) = delete;
+  Wrapper& operator=(const Wrapper&) = delete;
+
+  ~Wrapper() = default;
+
+  /// Return a pointer to the underlying C object
+  T* cobj() { return _ptr.get(); }
+
+  /// Return a pointer to the underlying C object
+  const T* cobj() const { return _ptr.get(); }
+
+protected:
+  friend class Optional<T>;
+
+  explicit Wrapper(std::nullptr_t)
+    : _ptr{nullptr}
+  {}
+
+  void reset() { _ptr.reset(); }
+
+  std::unique_ptr<T, Deleter> _ptr;
+};
+
+/**
+   @}
+*/
+
+} // namespace detail
+} // namespace serd
+
+#endif // SERD_DETAIL_WRAPPER_HPP