From 72dc439584ef3cdf7a75dfae5cf085c259acd654 Mon Sep 17 00:00:00 2001
From: dvtate <toast27@gmail.com>
Date: Fri, 10 Oct 2025 15:44:48 -0500
Subject: [PATCH] Add basic_fields::contains member function

---
 include/boost/beast/http/fields.hpp           | 14 +++++++++++
 include/boost/beast/http/impl/fields.hpp      | 24 ++++++++++++++++---
 include/boost/beast/websocket/impl/accept.hpp |  4 ++--
 test/beast/http/fields.cpp                    | 14 +++++++++++
 4 files changed, 51 insertions(+), 5 deletions(-)

diff --git a/include/boost/beast/http/fields.hpp b/include/boost/beast/http/fields.hpp
index d799d3ab..8dd92a44 100644
--- a/include/boost/beast/http/fields.hpp
+++ b/include/boost/beast/http/fields.hpp
@@ -647,6 +647,20 @@ public:
     //
     //--------------------------------------------------------------------------
 
+    /** Returns `true` if there is a field with the specified name.
+
+        @param name The field name.
+    */
+    bool
+    contains(field name) const;
+
+    /** Returns `true` if there is a field with the specified name.
+
+        @param name The field name. It is interpreted as a case-insensitive string.
+    */
+    bool
+    contains(string_view name) const;
+
     /** Return the number of fields with the specified name.
 
         @param name The field name.
diff --git a/include/boost/beast/http/impl/fields.hpp b/include/boost/beast/http/impl/fields.hpp
index bd3e74a9..b42a3ccd 100644
--- a/include/boost/beast/http/impl/fields.hpp
+++ b/include/boost/beast/http/impl/fields.hpp
@@ -659,6 +659,24 @@ swap(
 //
 //------------------------------------------------------------------------------
 
+template<class Allocator>
+inline
+bool
+basic_fields<Allocator>::
+contains(field name) const
+{
+    BOOST_ASSERT(name != field::unknown);
+    return contains(to_string(name));
+}
+
+template<class Allocator>
+bool
+basic_fields<Allocator>::
+contains(string_view name) const
+{
+    return find(name) != end();
+}
+
 template<class Allocator>
 inline
 std::size_t
@@ -835,7 +853,7 @@ bool
 basic_fields<Allocator>::
 has_content_length_impl() const
 {
-    return count(field::content_length) > 0;
+    return contains(field::content_length);
 }
 
 template<class Allocator>
@@ -999,7 +1017,7 @@ insert_element(element& e)
         set_.upper_bound(e.name_string(), key_compare{});
     if(before == set_.begin())
     {
-        BOOST_ASSERT(count(e.name_string()) == 0);
+        BOOST_ASSERT(! contains(e.name_string()));
         set_.insert_before(before, e);
         list_.push_back(e);
         return;
@@ -1008,7 +1026,7 @@ insert_element(element& e)
     // VFALCO is it worth comparing `field name` first?
     if(! beast::iequals(e.name_string(), last->name_string()))
     {
-        BOOST_ASSERT(count(e.name_string()) == 0);
+        BOOST_ASSERT(! contains(e.name_string()));
         set_.insert_before(before, e);
         list_.push_back(e);
         return;
diff --git a/include/boost/beast/websocket/impl/accept.hpp b/include/boost/beast/websocket/impl/accept.hpp
index 0fab245d..e20b4d1c 100644
--- a/include/boost/beast/websocket/impl/accept.hpp
+++ b/include/boost/beast/websocket/impl/accept.hpp
@@ -77,7 +77,7 @@ build_response(
         {
             decorator_opt(res);
             decorator(res);
-            if(! res.count(http::field::server))
+            if(! res.contains(http::field::server))
                 res.set(http::field::server,
                     string_view(BOOST_BEAST_VERSION_STRING));
         };
@@ -97,7 +97,7 @@ build_response(
         return err(error::bad_http_version);
     if(req.method() != http::verb::get)
         return err(error::bad_method);
-    if(! req.count(http::field::host))
+    if(! req.contains(http::field::host))
         return err(error::no_host);
     {
         auto const it = req.find(http::field::connection);
diff --git a/test/beast/http/fields.cpp b/test/beast/http/fields.cpp
index 71a0fb39..c93a493a 100644
--- a/test/beast/http/fields.cpp
+++ b/test/beast/http/fields.cpp
@@ -476,6 +476,20 @@ public:
             BEAST_THROWS(f.set(big_name, ""),                 boost::system::system_error);
             BEAST_THROWS(f.set("", big_value),                boost::system::system_error);
         }
+
+        {
+            fields f;
+            BEAST_EXPECT(! f.contains("Content-Type"));
+            f.set("Content-Type", "text/html");
+            BEAST_EXPECT(f.contains("Content-Type"));
+            BEAST_EXPECT(f.contains("content-type"));
+            BEAST_EXPECT(! f.contains(field::user_agent));
+
+            f.insert("AA", "a");
+            f.insert("AA", "b");
+            f.insert("AA", "c");
+            BEAST_EXPECT(f.contains("AA"));            
+        }
     }
 
     struct sized_body