Remove more obsolete STL from message.c++.

c++/src/capnp/message.c++

@@ -25,9 +25,6 @@
 #include "arena.h"
 #include "orphan.h"
 #include <stdlib.h>
-#include <exception>
-#include <string>
-#include <vector>
 #include <errno.h>
 
 namespace capnp {
@@ -58,7 +55,7 @@ bool MessageReader::isCanonical() {
     static_assert(sizeof(_::ReaderArena) <= sizeof(arenaSpace),
         "arenaSpace is too small to hold a ReaderArena.  Please increase it.  This will break "
         "ABI compatibility.");
-    new(arena()) _::ReaderArena(this);
+    kj::ctor(*arena(), this);
     allocatedArena = true;
   }
 
@@ -89,7 +86,7 @@ AnyPointer::Reader MessageReader::getRootInternal() {
     static_assert(sizeof(_::ReaderArena) <= sizeof(arenaSpace),
         "arenaSpace is too small to hold a ReaderArena.  Please increase it.  This will break "
         "ABI compatibility.");
-    new(arena()) _::ReaderArena(this);
+    kj::ctor(*arena(), this);
     allocatedArena = true;
   }
 
@@ -199,10 +196,6 @@ kj::ArrayPtr<const word> SegmentArrayMessageReader::getSegment(uint id) {
 
 // -------------------------------------------------------------------
 
-struct MallocMessageBuilder::MoreSegments {
-  std::vector<void*> segments;
-};
-
 MallocMessageBuilder::MallocMessageBuilder(
     uint firstSegmentWords, AllocationStrategy allocationStrategy)
     : nextSize(firstSegmentWords), allocationStrategy(allocationStrategy),
@@ -233,10 +226,8 @@ MallocMessageBuilder::~MallocMessageBuilder() noexcept(false) {
       }
     }
 
-    KJ_IF_MAYBE(s, moreSegments) {
-      for (void* ptr: s->get()->segments) {
-        free(ptr);
-      }
+    for (void* ptr: moreSegments) {
+      free(ptr);
     }
   }
 }
@@ -273,15 +264,7 @@ kj::ArrayPtr<word> MallocMessageBuilder::allocateSegment(uint minimumSize) {
     // After the first segment, we want nextSize to equal the total size allocated so far.
     if (allocationStrategy == AllocationStrategy::GROW_HEURISTICALLY) nextSize = size;
   } else {
-    MoreSegments* segments;
-    KJ_IF_MAYBE(s, moreSegments) {
-      segments = *s;
-    } else {
-      auto newSegments = kj::heap<MoreSegments>();
-      segments = newSegments;
-      moreSegments = mv(newSegments);
-    }
-    segments->segments.push_back(result);
+    moreSegments.add(result);
     if (allocationStrategy == AllocationStrategy::GROW_HEURISTICALLY) {
       // set nextSize = min(nextSize+size, MAX_SEGMENT_WORDS)
       // while protecting against possible overflow of (nextSize+size)

c++/src/capnp/message.h

@@ -23,6 +23,7 @@
 #include <kj/memory.h>
 #include <kj/mutex.h>
 #include <kj/debug.h>
+#include <kj/vector.h>
 #include "common.h"
 #include "layout.h"
 #include "any.h"
@@ -387,9 +388,7 @@ private:
   bool returnedFirstSegment;
 
   void* firstSegment;
-
-  struct MoreSegments;
-  kj::Maybe<kj::Own<MoreSegments>> moreSegments;
+  kj::Vector<void*> moreSegments;
 };
 
 class FlatMessageBuilder: public MessageBuilder {