diff --git a/include/boost/static_string/detail/static_string.hpp b/include/boost/static_string/detail/static_string.hpp
index 08e68c1..23efab2 100644
--- a/include/boost/static_string/detail/static_string.hpp
+++ b/include/boost/static_string/detail/static_string.hpp
@@ -569,6 +569,22 @@ find_first_of(
   return last;
 }
 
+// Check if a pointer lies within a range without unspecified behavior, allowing it to be used in a constant evaluation
+template<typename T>
+BOOST_STATIC_STRING_CPP14_CONSTEXPR
+inline
+bool
+is_inside(
+    const T* src_first, 
+    const T* src_last,
+    const T* ptr)
+{
+  for (; src_first != src_last; ++src_first)
+    if (src_first == ptr)
+      return true;
+  return false;
+}
+
 } // detail
 } // static_string
 } // boost
diff --git a/include/boost/static_string/impl/static_string.hpp b/include/boost/static_string/impl/static_string.hpp
index d72d1a4..dddd924 100644
--- a/include/boost/static_string/impl/static_string.hpp
+++ b/include/boost/static_string/impl/static_string.hpp
@@ -631,8 +631,7 @@ replace(
   const auto curr_data = data();
   BOOST_STATIC_STRING_THROW_IF(
       pos > curr_size, std::out_of_range{"pos > size()"});
-  if (pos + n1 >= curr_size)
-    n1 = curr_size - pos;
+  n1 = (std::min)(n1, curr_size - pos);
   return replace(curr_data + pos, curr_data + pos + n1, s, s + n2);
 }
 
@@ -653,8 +652,7 @@ replace(
   BOOST_STATIC_STRING_THROW_IF(
       curr_size - (std::min)(n1, curr_size - pos) >= max_size() - n2,
       std::length_error{"replaced string exceeds max_size()"});
-  if (pos + n1 >= curr_size)
-    n1 = curr_size - pos;
+  n1 = (std::min)(n1, curr_size - pos);
   Traits::move(&curr_data[pos + n2], &curr_data[pos + n1], curr_size - pos - n1 + 1);
   Traits::assign(&curr_data[pos], n2, c);
   this->set_size(curr_size + (n2 - n1));
@@ -684,8 +682,7 @@ replace(
   BOOST_STATIC_STRING_THROW_IF(
     curr_size - (std::min)(n1, curr_size - pos) >= max_size() - n2,
     std::length_error{"replaced string exceeds max_size()"});
-  if (pos + n1 >= curr_size)
-    n1 = curr_size - pos;
+  n1 = (std::min)(n1, curr_size - pos);
   const bool inside = s <= &curr_data[curr_size] && s >= curr_data;
   if (inside && size_type(s - curr_data) == pos && n1 == n2)
     return *this;
@@ -753,8 +750,7 @@ replace(
   // Rotate to the correct order. [i2, end] will now start with the replaced string, continue to the existing string not being replaced, and end with a null terminator
   std::rotate(&curr_data[pos], &curr_data[curr_size + 1], &curr_data[curr_size + n2 + 1]);
   // Cap the size
-  if (pos + n1 >= curr_size)
-    n1 = curr_size - pos;
+  n1 = (std::min)(n1, curr_size - pos);
   // Move everything from the end of the splice point to the end of the rotated string to the begining of the splice point
   Traits::move(&curr_data[pos + n2], &curr_data[pos + n2 + n1], (curr_size + (n2 - n1)) - pos);
   this->set_size(curr_size + (n2 - n1));