Merge bitcoin/bitcoin#24253: Remove broken and unused CDataStream methods

fa1b227a727a5056c6fbc7e4f33c19aeb5207718 Remove broken and unused CDataStream methods (MarcoFalke)
faee5f8dc23cd2fcfb6ad62a1d46ad3020ef0c5c test: Create fresh CDataStream each time (MarcoFalke)
fa71114926490e84c9222d315a95684d250e8e34 test: Inline expected_xor (MarcoFalke)

Pull request description:

  The `insert` and `erase` methods have many issues:

  * They are unused
  * They are confusing and hard to read, as they implement "special cases" for optimization, that isn't needed
  * They are broken (See https://github.com/bitcoin/bitcoin/pull/24231)
  * Fixing them leads to mingw compile errors (See https://github.com/bitcoin/bitcoin/pull/24231#issuecomment-1029286985)

  Fix all issues by removing them

ACKs for top commit:
  laanwj:
    Code review ACK fa1b227a727a5056c6fbc7e4f33c19aeb5207718

Tree-SHA512: 9d9e5d42e6ffc5ae82bdb67cfb5b50b45977ae674acee6ff99092560aebf2fc7e4584ded614e190db0663226fa198e34350517cd7ee57d518de22e9568bc349a

1 files changed, 0 insertions, 67 deletions

diff --git a/src/streams.h b/src/streams.h
index 2f26be6dd8..cf8b4eb96f 100644
--- a/src/streams.h
+++ b/src/streams.h
@@ -240,76 +240,9 @@ public:
     const_reference operator[](size_type pos) const  { return vch[pos + nReadPos]; }
     reference operator[](size_type pos)              { return vch[pos + nReadPos]; }
     void clear()                                     { vch.clear(); nReadPos = 0; }
-    iterator insert(iterator it, const value_type x) { return vch.insert(it, x); }
-    void insert(iterator it, size_type n, const value_type x) { vch.insert(it, n, x); }
     value_type* data()                               { return vch.data() + nReadPos; }
     const value_type* data() const                   { return vch.data() + nReadPos; }
 
-    void insert(iterator it, std::vector<value_type>::const_iterator first, std::vector<value_type>::const_iterator last)
-    {
-        if (last == first) return;
-        assert(last - first > 0);
-        if (it == vch.begin() + nReadPos && (unsigned int)(last - first) <= nReadPos)
-        {
-            // special case for inserting at the front when there's room
-            nReadPos -= (last - first);
-            memcpy(&vch[nReadPos], &first[0], last - first);
-        }
-        else
-            vch.insert(it, first, last);
-    }
-
-    void insert(iterator it, const value_type* first, const value_type* last)
-    {
-        if (last == first) return;
-        assert(last - first > 0);
-        if (it == vch.begin() + nReadPos && (unsigned int)(last - first) <= nReadPos)
-        {
-            // special case for inserting at the front when there's room
-            nReadPos -= (last - first);
-            memcpy(&vch[nReadPos], &first[0], last - first);
-        }
-        else
-            vch.insert(it, first, last);
-    }
-
-    iterator erase(iterator it)
-    {
-        if (it == vch.begin() + nReadPos)
-        {
-            // special case for erasing from the front
-            if (++nReadPos >= vch.size())
-            {
-                // whenever we reach the end, we take the opportunity to clear the buffer
-                nReadPos = 0;
-                return vch.erase(vch.begin(), vch.end());
-            }
-            return vch.begin() + nReadPos;
-        }
-        else
-            return vch.erase(it);
-    }
-
-    iterator erase(iterator first, iterator last)
-    {
-        if (first == vch.begin() + nReadPos)
-        {
-            // special case for erasing from the front
-            if (last == vch.end())
-            {
-                nReadPos = 0;
-                return vch.erase(vch.begin(), vch.end());
-            }
-            else
-            {
-                nReadPos = (last - vch.begin());
-                return last;
-            }
-        }
-        else
-            return vch.erase(first, last);
-    }
-
     inline void Compact()
     {
         vch.erase(vch.begin(), vch.begin() + nReadPos);