diff --git a/std/bitmanip.d b/std/bitmanip.d
index 86df657e613..05c74b26b69 100644
--- a/std/bitmanip.d
+++ b/std/bitmanip.d
@@ -3773,57 +3773,6 @@ void append(T, Endian endianness = Endian.bigEndian, R)(R range, T value)
     }
 }
 
-/**
-Counts the number of trailing zeros in the binary representation of $(D value).
-For signed integers, the sign bit is included in the count.
-*/
-private uint countTrailingZeros(T)(T value) @nogc pure nothrow
-    if (isIntegral!T)
-{
-    import core.bitop : bsf;
-    // bsf doesn't give the correct result for 0.
-    if (!value)
-        return 8 * T.sizeof;
-    else
-        return bsf(value);
-}
-
-///
-@safe unittest
-{
-    assert(countTrailingZeros(1) == 0);
-    assert(countTrailingZeros(0) == 32);
-    assert(countTrailingZeros(int.min) == 31);
-    assert(countTrailingZeros(256) == 8);
-}
-
-@safe unittest
-{
-    import std.meta;
-    foreach (T; AliasSeq!(byte, ubyte, short, ushort, int, uint, long, ulong))
-    {
-        assert(countTrailingZeros(cast(T)0) == 8 * T.sizeof);
-        assert(countTrailingZeros(cast(T)1) == 0);
-        assert(countTrailingZeros(cast(T)2) == 1);
-        assert(countTrailingZeros(cast(T)3) == 0);
-        assert(countTrailingZeros(cast(T)4) == 2);
-        assert(countTrailingZeros(cast(T)5) == 0);
-        assert(countTrailingZeros(cast(T)64) == 6);
-        static if (isSigned!T)
-        {
-            assert(countTrailingZeros(cast(T)-1) == 0);
-            assert(countTrailingZeros(T.min) == 8 * T.sizeof - 1);
-        }
-        else
-        {
-            assert(countTrailingZeros(T.max) == 0);
-        }
-    }
-    assert(countTrailingZeros(1_000_000) == 6);
-    foreach (i; 0..63)
-        assert(countTrailingZeros(1UL << i) == i);
-}
-
 /**
 Counts the number of set bits in the binary representation of $(D value).
 For signed integers, the sign bit is included in the count.
@@ -3914,9 +3863,14 @@ private struct BitsSet(T)
     this(T value, size_t startIndex = 0)
     {
         _value = value;
-        immutable n = countTrailingZeros(value);
-        _index = startIndex + n;
-        _value >>>= n;
+        // Further calculation is only valid and needed when the range is non-empty.
+        if (!_value)
+            return;
+
+        import core.bitop : bsf;
+        immutable trailingZerosCount = bsf(value);
+        _value >>>= trailingZerosCount;
+        _index = startIndex + trailingZerosCount;
     }
 
     @property size_t front()
@@ -3934,9 +3888,14 @@ private struct BitsSet(T)
         assert(_value, "Cannot call popFront on empty range.");
 
         _value >>>= 1;
-        immutable n = countTrailingZeros(_value);
-        _value >>>= n;
-        _index += n + 1;
+        // Further calculation is only valid and needed when the range is non-empty.
+        if (!_value)
+            return;
+
+        import core.bitop : bsf;
+        immutable trailingZerosCount = bsf(_value);
+        _value >>>= trailingZerosCount;
+        _index += trailingZerosCount + 1;
     }
 
     @property auto save()