X-Git-Url: https://mattmccutchen.net/bigint/bigint.git/blobdiff_plain/83a639e66e094c683b48215a895f6d35e9d60d32..61a5a343eee6e3a0f3b533acf167dd8d0c4e5197:/BigInteger.cc

diff --git a/BigInteger.cc b/BigInteger.cc
index 56f30ab..3b23aa1 100644
--- a/BigInteger.cc
+++ b/BigInteger.cc
@@ -13,11 +13,18 @@ void BigInteger::operator =(const BigInteger &x) {
 BigInteger::BigInteger(const Blk *b, Index blen, Sign s) : mag(b, blen) {
 	switch (s) {
 	case zero:
+		if (!mag.isZero())
+			throw "BigInteger::BigInteger(const Blk *, Index, Sign): Cannot use a sign of zero with a nonzero magnitude";
+		sign = zero;
+		break;
 	case positive:
 	case negative:
+		// If the magnitude is zero, force the sign to zero.
 		sign = mag.isZero() ? zero : s;
 		break;
 	default:
+		/* g++ seems to be optimizing out this case on the assumption
+		 * that the sign is a valid member of the enumeration.  Oh well. */
 		throw "BigInteger::BigInteger(const Blk *, Index, Sign): Invalid sign";
 	}
 }
@@ -25,12 +32,19 @@ BigInteger::BigInteger(const Blk *b, Index blen, Sign s) : mag(b, blen) {
 BigInteger::BigInteger(const BigUnsigned &x, Sign s) : mag(x) {
 	switch (s) {
 	case zero:
+		if (!mag.isZero())
+			throw "BigInteger::BigInteger(const BigUnsigned &, Sign): Cannot use a sign of zero with a nonzero magnitude";
+		sign = zero;
+		break;
 	case positive:
 	case negative:
+		// If the magnitude is zero, force the sign to zero.
 		sign = mag.isZero() ? zero : s;
 		break;
 	default:
-		throw "BigInteger::BigInteger(Blk *, Index, Sign): Invalid sign";
+		/* g++ seems to be optimizing out this case on the assumption
+		 * that the sign is a valid member of the enumeration.  Oh well. */
+		throw "BigInteger::BigInteger(const BigUnsigned &, Sign): Invalid sign";
 	}
 }