[PATCH v1 5/8] gdb support: add gdb::replace algorithm for iterators and ranges

[Matthieu Longo <matthieu.longo@arm.com>]

Add a gdb::replace helper that mirrors the behavior of std::replace
for iterator pairs, together with a convenience overload accepting a
range.

This provides a C++17-compatible replacement for the C++20 std::replace/
std::ranges::replace algorithms, allowing callers to use a consistent
interface until GDB transitions to C++20. The helpers should be removed
once the C++ standard library implementations become available.
---
 gdbsupport/array-view.h | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/gdbsupport/array-view.h b/gdbsupport/array-view.h
index e7baea728d4..fa2b8889614 100644
--- a/gdbsupport/array-view.h
+++ b/gdbsupport/array-view.h
@@ -226,6 +226,32 @@ void copy (array_view<U> src, array_view<T> dest)
     std::copy_backward (src.begin (), src.end (), dest.end ());
 }
 
+/* Replace all occurrences of a value in the provided range.
+
+   Note: this helper is a reimplementation of std::replace, only available
+   from C++20 onwards, and consequently, should be removed once we switch
+   to C++20.  */
+
+template <class ForwardIt, typename T>
+void replace (ForwardIt first, ForwardIt last,
+	      const T &old_value, const T &new_value)
+{
+  for (auto it = first; it != last; ++it)
+  {
+    if (*it == old_value)
+      *it = new_value;
+  }
+}
+
+/* Replace all occurrences of a value in the provided array view.
+   Note: from C++20 onwards, std::ranges::replace should be used instead.  */
+
+template <class Range, typename T>
+void replace (Range r, const T &old_value, const T &new_value)
+{
+  replace (r.begin (), r.end (), old_value, new_value);
+}
+
 /* Compare LHS and RHS for (deep) equality.  That is, whether LHS and
    RHS have the same sizes, and whether each pair of elements of LHS
    and RHS at the same position compares equal.  */
-- 
2.55.0