[gcc r11-9134] libstdc++: Remove __gnu_cxx::rope::erase(size_type) [PR102048]

[gcc r11-9134] libstdc++: Remove __gnu_cxx::rope::erase(size_type) [PR102048]

[Jonathan Wakely]

https://gcc.gnu.org/g:a1dc688940ffade63452c8f9d80fd4b3204e5f40

commit r11-9134-ga1dc688940ffade63452c8f9d80fd4b3204e5f40
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Wed Aug 25 16:42:49 2021 +0100

    libstdc++: Remove __gnu_cxx::rope::erase(size_type) [PR102048]
    
    This function claims to remove a single character at index p, but it
    actually removes p+1 characters beginning at p. So r.erase(0) removes
    the first character, but r.erase(1) removes the second and third, and
    r.erase(2) removes the second, third and fourth. This is not a useful
    API.
    
    The overload is present in the SGI STL <stl_rope.h> header that we
    imported, but it isn't documented in the API reference. The erase
    overloads that are documented are:
    
    erase(const iterator& p)
    erase(const iterator& f, const iterator& l)
    erase(size_type i, size_type n);
    
    Having an erase(size_type p) overload that erases a single character (as
    the comment says it does) might be useful, but would be inconsistent
    with std::basic_string::erase(size_type p = 0, size_type n = npos),
    which erases from p to the end of the string when called with a single
    argument.
    
    Since the function isn't part of the documented API, doesn't do what it
    claims to do (or anything useful) and "fixing" it would leave it
    inconsistent with basic_string, I'm just removing that overload.
    
    libstdc++-v3/ChangeLog:
    
            PR libstdc++/102048
            * include/ext/rope (rope::erase(size_type)): Remove broken
            function.
    
    (cherry picked from commit 2cd229dec8d6716938de5052479d059d306969da)

Diff:
---
 libstdc++-v3/include/ext/rope | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/libstdc++-v3/include/ext/rope b/libstdc++-v3/include/ext/rope
index 81e4f23708f..f6461028722 100644
--- a/libstdc++-v3/include/ext/rope
+++ b/libstdc++-v3/include/ext/rope
@@ -2394,11 +2394,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	this->_M_tree_ptr = __result;
       }
 
-      // Erase, single character
-      void
-      erase(size_type __p)
-      { erase(__p, __p + 1); }
-
       // Insert, iterator variants.
       iterator
       insert(const iterator& __p, const rope& __r)