Add move assignment and constructor operators to BigInt. On macro benchmarks

(timing the test suite) there doesn't seem to be much of a difference either
way, but putting printfs in the implementations shows they are being used.
Since they pretty much can't possibly hurt (right?) and might well help a
lot in certain cases, it's worth including.

Todo: adding overloads to binary operators taking move operations might
be nice. Details in http://cpp-next.com/archive/2009/09/making-your-next-move/

2 files changed, 40 insertions, 4 deletions

diff --git a/src/math/bigint/bigint.cpp b/src/math/bigint/bigint.cpp
index 7592ec439..36739f047 100644
--- a/src/math/bigint/bigint.cpp
+++ b/src/math/bigint/bigint.cpp
@@ -40,7 +40,7 @@ BigInt::BigInt(Sign s, u32bit size)
    }
 
 /*
-* Construct a BigInt from a "raw" BigInt
+* Copy constructor
 */
 BigInt::BigInt(const BigInt& b)
    {
@@ -100,6 +100,29 @@ BigInt::BigInt(RandomNumberGenerator& rng, u32bit bits)
    randomize(rng, bits);
    }
 
+/**
+* Move constructor
+*/
+BigInt::BigInt(BigInt&& other)
+   {
+   reg.swap(other.reg);
+   signedness = other.signedness;
+   }
+
+/**
+* Move assignment
+*/
+BigInt& BigInt::operator=(BigInt&& other)
+   {
+   if(this != &other)
+      {
+      reg.swap(other.reg);
+      signedness = other.signedness;
+      }
+
+   return (*this);
+   }
+
 /*
 * Swap this BigInt with another
 */
diff --git a/src/math/bigint/bigint.h b/src/math/bigint/bigint.h
index 4f7f6f5bd..3db9a1a04 100644
--- a/src/math/bigint/bigint.h
+++ b/src/math/bigint/bigint.h
@@ -425,10 +425,14 @@ class BOTAN_DLL BigInt
      BigInt(u64bit n);
 
      /**
-     * Copy-Constructor: clone given BigInt
-     * @param bigint the BigInt to clone
+     * Copy constructor
      */
-     BigInt(const BigInt& bigint);
+     BigInt(const BigInt& other);
+
+     /**
+     * Assignment operator
+     */
+     BigInt& operator=(const BigInt&) = default;
 
      /**
      * Create BigInt from a string.
@@ -471,6 +475,15 @@ class BOTAN_DLL BigInt
      */
      BigInt(NumberType type, u32bit n);
 
+     /**
+     * Move constructor
+     */
+     BigInt(BigInt&& other);
+
+     /**
+     * Move assignment
+     */
+     BigInt& operator=(BigInt&& other);
    private:
       SecureVector<word> reg;
       Sign signedness;