[buddy] Enable C++11 and add a move constructor/assignment operator.

* configure.ac: Enable C++11 mode.
* src/bdd.h: Use noexport, and add a move constructor and
move assignment operator.  The move version of these method
do not have to increment the reference counter, saving time.
On a small test run, this change saved 24% of the calls to
bdd_addref_nc().

buddy/ChangeLog

+2014-01-06  Alexandre Duret-Lutz  <adl@lrde.epita.fr>
+
+	Enable C++11 and add a move constructor/assignment operator.
+
+	* configure.ac: Enable C++11 mode.
+	* src/bdd.hh: Use noexport, and add a move constructor and
+	move assignment operator.  The move version of these method
+	do not have to increment the reference counter, saving time.
+	On a small test run, this change saved 24% of the calls to
+	bdd_addref_nc().
+
 2013-06-23  Alexandre Duret-Lutz  <adl@lrde.epita.fr>
 
 	Restrict the number of exported symbols.

buddy/configure.ac

@@ -43,6 +43,41 @@ if test x$enable_warnings = xyes; then
   CF_GCC_WARNINGS
 fi
 
+# Turn on C++11 support
+AC_LANG(C++)
+m4_define([_AX_CXX_COMPILE_STDCXX_11_testbody],
+[AC_LANG_SOURCE([#include <memory>
+#include <string>
+
+   template <typename T>
+    struct check
+    {
+      static_assert(sizeof(int) <= sizeof(T), "not big enough");
+    };
+
+    typedef check<check<bool>> right_angle_brackets;
+
+    auto f = std::make_shared<std::string>("shared_ptr");
+
+    int a;
+    decltype(a) b;
+
+    typedef check<int> check_type;
+    check_type c;
+    check_type&& cr = static_cast<check_type&&>(c);
+
+    auto d = a;
+])])
+
+for f in -std=c++11 '-std=c++11 -stdlib=libc++' -std=c++0x
+do
+  AX_CHECK_COMPILE_FLAG([$f], [CXXFLAGS="$CXXFLAGS $f" stdpass=true], [], [],
+                        [_AX_CXX_COMPILE_STDCXX_11_testbody])
+  ${stdpass-false} && break
+done
+if ! "${stdpass-false}"; then
+  AC_ERROR([unable to turn on C++11 mode with this compiler])
+fi
 
 AC_CONFIG_HEADERS([config.h])
 

buddy/src/bdd.h

@@ -487,13 +487,33 @@ class BUDDY_API bdd
 {
  public:
 
-   bdd(void)         { root=0; }
-   bdd(const bdd &r) { root=r.root; if (root > 1) bdd_addref_nc(root); }
-   ~bdd(void)        { if (root > 1) bdd_delref_nc(root); }
-
-   int id(void) const;
-
-   bdd& operator=(const bdd &r);
+   bdd(void) noexcept
+   {
+     root=0;
+   }
+   bdd(const bdd &r) noexcept
+   {
+     root=r.root;
+     if (root > 1)
+       bdd_addref_nc(root);
+   }
+
+   bdd(bdd&& r) noexcept
+   {
+     root=r.root;
+     r.root = 0;
+   }
+
+   ~bdd(void) noexcept
+   {
+     if (root > 1)
+       bdd_delref_nc(root);
+   }
+
+   int id(void) const noexcept;
+
+   bdd& operator=(const bdd &r) noexcept;
+   bdd& operator=(bdd&& r) noexcept;
 
    bdd operator&(const bdd &r) const;
    bdd& operator&=(const bdd &r);
@@ -510,14 +530,14 @@ class BUDDY_API bdd
    bdd operator<(const bdd &r) const;
    bdd operator<<(const bdd &r) const;
    bdd& operator<<=(const bdd &r);
-   int operator==(const bdd &r) const;
-   int operator!=(const bdd &r) const;
+   int operator==(const bdd &r) const noexcept;
+   int operator!=(const bdd &r) const noexcept;
 
 private:
    BDD root;
 
-   bdd(BDD r) { root=r; if (root > 1) bdd_addref_nc(root); }
-   bdd& operator=(BDD r);
+   bdd(BDD r) noexcept { root=r; if (root > 1) bdd_addref_nc(root); }
+   bdd& operator=(BDD r) noexcept;
 
    friend int      bdd_init(int, int);
    friend int      bdd_setvarnum(int);
@@ -543,7 +563,7 @@ private:
    friend bdd      bdd_imp(const bdd &, const bdd &);
    friend bdd      bdd_biimp(const bdd &, const bdd &);
    friend bdd      bdd_setxor(const bdd &, const bdd &);
-   friend int      bdd_implies(const bdd &, const bdd &);
+   friend int      bdd_implies(const bdd &, const bdd &) noexcept;
    friend bdd      bdd_ite(const bdd &, const bdd &, const bdd &);
    friend bdd      bdd_restrict(const bdd &, const bdd &);
    friend bdd      bdd_constrain(const bdd &, const bdd &);
@@ -704,7 +724,7 @@ inline bdd bdd_biimp(const bdd &l, const bdd &r)
 inline bdd bdd_setxor(const bdd &l, const bdd &r)
 { return bdd_setxor(l.root, r.root); }
 
-inline int bdd_implies(const bdd &l, const bdd &r)
+inline int bdd_implies(const bdd &l, const bdd &r) noexcept
 { return bdd_implies(l.root, r.root); }
 
 inline bdd bdd_ite(const bdd &f, const bdd &g, const bdd &h)
@@ -834,7 +854,7 @@ inline int bdd_addvarblock(const bdd &v, int f)
 
 /*=== Inline C++ functions =============================================*/
 
-inline int bdd::id(void) const
+inline int bdd::id(void) const noexcept
 { return root; }
 
 inline bdd bdd::operator&(const bdd &r) const
@@ -882,13 +902,13 @@ inline bdd bdd::operator<<(const bdd &r) const
 inline bdd& bdd::operator<<=(const bdd &r)
 { return (*this=bdd_apply(*this,r,bddop_invimp)); }
 
-inline int bdd::operator==(const bdd &r) const
+inline int bdd::operator==(const bdd &r) const noexcept
 { return r.root==root; }
 
-inline int bdd::operator!=(const bdd &r) const
+inline int bdd::operator!=(const bdd &r) const noexcept
 { return r.root!=root; }
 
-inline bdd& bdd::operator=(const bdd &r)
+inline bdd& bdd::operator=(const bdd &r) noexcept
 {
   if (__likely(root != r.root))
     {
@@ -901,7 +921,16 @@ inline bdd& bdd::operator=(const bdd &r)
   return *this;
 }
 
-inline bdd& bdd::operator=(int r)
+inline bdd& bdd::operator=(bdd&& r) noexcept
+{
+  if (root > 1)
+    bdd_delref_nc(root);
+  root = r.root;
+  r.root = 0;
+  return *this;
+}
+
+inline bdd& bdd::operator=(int r) noexcept
 {
   if (__likely(root != r))
     {