Make pdfium::span<> be based off of UnownedPtr<>.

Because we can get the lifetime check for free if we do this. This
requires adding some "constexpr/noexcept" to UnownedPtr to make the
types line up with what span.h requires.

Change-Id: I45918f8723122082036eed959f769644ab4c509f
Reviewed-on: https://pdfium-review.googlesource.com/29672
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

1 files changed, 7 insertions, 7 deletions

diff --git a/core/fxcrt/unowned_ptr.h b/core/fxcrt/unowned_ptr.h
index b1c9c66b3e..0e3bf9e09b 100644
--- a/core/fxcrt/unowned_ptr.h
+++ b/core/fxcrt/unowned_ptr.h
@@ -40,25 +40,25 @@ namespace fxcrt {
 template <class T>
 class UnownedPtr {
  public:
-  UnownedPtr() = default;
-  UnownedPtr(const UnownedPtr& that) : UnownedPtr(that.Get()) {}
+  constexpr UnownedPtr() noexcept = default;
+  constexpr UnownedPtr(const UnownedPtr& that) noexcept = default;
 
   template <typename U>
-  explicit UnownedPtr(U* pObj) : m_pObj(pObj) {}
+  explicit constexpr UnownedPtr(U* pObj) noexcept : m_pObj(pObj) {}
 
   // Deliberately implicit to allow returning nullptrs.
   // NOLINTNEXTLINE(runtime/explicit)
-  UnownedPtr(std::nullptr_t ptr) {}
+  constexpr UnownedPtr(std::nullptr_t ptr) noexcept {}
 
   ~UnownedPtr() { ProbeForLowSeverityLifetimeIssue(); }
 
-  UnownedPtr& operator=(T* that) {
+  UnownedPtr& operator=(T* that) noexcept {
     ProbeForLowSeverityLifetimeIssue();
     m_pObj = that;
     return *this;
   }
 
-  UnownedPtr& operator=(const UnownedPtr& that) {
+  UnownedPtr& operator=(const UnownedPtr& that) noexcept {
     ProbeForLowSeverityLifetimeIssue();
     if (*this != that)
       m_pObj = that.Get();
@@ -81,7 +81,7 @@ class UnownedPtr {
     return !(*this == that);
   }
 
-  T* Get() const { return m_pObj; }
+  T* Get() const noexcept { return m_pObj; }
 
   T* Release() {
     ProbeForLowSeverityLifetimeIssue();