Mark exception_wrapper constructor as noexcept

Summary: Constructing an `exception_wrapper` from an `std::exception_ptr` and a reference to an exception could never throw an exception, but was not marked `noexcept`. So annotate it.

Reviewed By: yfeldblum, lewissbaker

Differential Revision: D9351489

fbshipit-source-id: 858299330b376360fc6420b6c901ab846d577854

folly/ExceptionWrapper-inl.h

@@ -99,7 +99,7 @@ static_assert(
 
 inline std::uintptr_t exception_wrapper::ExceptionPtr::as_int_(
     std::exception_ptr const& ptr,
-    std::exception const& e) {
+    std::exception const& e) noexcept {
   if (!kMicrosoftAbiVer) {
     return reinterpret_cast<std::uintptr_t>(&e);
   } else {
@@ -130,7 +130,7 @@ inline std::uintptr_t exception_wrapper::ExceptionPtr::as_int_(
 }
 inline std::uintptr_t exception_wrapper::ExceptionPtr::as_int_(
     std::exception_ptr const&,
-    AnyException e) {
+    AnyException e) noexcept {
   return reinterpret_cast<std::uintptr_t>(e.typeinfo_) + 1;
 }
 inline bool exception_wrapper::ExceptionPtr::has_exception_() const {
@@ -333,7 +333,8 @@ inline exception_wrapper::~exception_wrapper() {
 }
 
 template <class Ex>
-inline exception_wrapper::exception_wrapper(std::exception_ptr ptr, Ex& ex)
+inline
+exception_wrapper::exception_wrapper(std::exception_ptr ptr, Ex& ex) noexcept
     : eptr_{ptr, ExceptionPtr::as_int_(ptr, ex)},
       vptr_(&ExceptionPtr::ops_) {
   assert(eptr_.ptr_);

folly/ExceptionWrapper.h

@@ -264,10 +264,10 @@ class exception_wrapper final {
 
     static std::uintptr_t as_int_(
         std::exception_ptr const& ptr,
-        std::exception const& e);
+        std::exception const& e) noexcept;
     static std::uintptr_t as_int_(
         std::exception_ptr const& ptr,
-        AnyException e);
+        AnyException e) noexcept;
     bool has_exception_() const;
     std::exception const* as_exception_() const;
     std::type_info const* as_type_() const;
@@ -418,7 +418,7 @@ class exception_wrapper final {
   //! \post `bool(*this)`
   //! \post `type() == typeid(ex)`
   template <class Ex>
-  exception_wrapper(std::exception_ptr ptr, Ex& ex);
+  exception_wrapper(std::exception_ptr ptr, Ex& ex) noexcept;
 
   //! \pre `typeid(ex) == typeid(typename decay<Ex>::type)`
   //! \post `bool(*this)`