Document the new overload of enum_from_string

.github/workflows/ci.yml

@@ -54,6 +54,11 @@ jobs:
             cxxstd: "03,11,14,17,20,2b"
             os: ubuntu-22.04
             install: g++-12
+          - toolset: gcc-13
+            cxxstd: "03,11,14,17,20,2b"
+            os: ubuntu-latest
+            container: ubuntu:23.04
+            install: g++-13
           - toolset: clang
             compiler: clang++-3.9
             cxxstd: "03,11,14"
@@ -122,12 +127,21 @@ jobs:
             cxxstd: "03,11,14,17,20,2b"
             os: ubuntu-22.04
             install: clang-15
+          - toolset: clang
+            compiler: clang++-16
+            cxxstd: "03,11,14,17,20,2b"
+            os: ubuntu-latest
+            container: ubuntu:23.04
+            install: clang-16
           - toolset: clang
             cxxstd: "03,11,14,17,2a"
             os: macos-11
           - toolset: clang
             cxxstd: "03,11,14,17,20,2b"
             os: macos-12
+          - toolset: clang
+            cxxstd: "03,11,14,17,20,2b"
+            os: macos-13
 
     runs-on: ${{matrix.os}}
     container: ${{matrix.container}}
@@ -143,11 +157,13 @@ jobs:
         if: matrix.container
         run: |
           apt-get update
-          apt-get -y install sudo python git g++
+          apt-get -y install sudo python3 git g++
 
       - name: Install packages
         if: matrix.install
-        run: sudo apt-get -y install ${{matrix.install}}
+        run: |
+          sudo apt-get update
+          sudo apt-get -y install ${{matrix.install}}
 
       - name: Setup Boost
         run: |
@@ -168,7 +184,7 @@ jobs:
           mkdir -p libs/$LIBRARY
           cp -r $GITHUB_WORKSPACE/* libs/$LIBRARY
           git submodule update --init tools/boostdep
-          python tools/boostdep/depinst/depinst.py --git_args "--jobs 3" -I example $LIBRARY
+          python3 tools/boostdep/depinst/depinst.py --git_args "--jobs 3" -I example $LIBRARY
           ./bootstrap.sh
           ./b2 -d0 headers
 
@@ -261,6 +277,7 @@ jobs:
           - os: ubuntu-22.04
           - os: macos-11
           - os: macos-12
+          - os: macos-13
 
     runs-on: ${{matrix.os}}
 
@@ -308,6 +325,7 @@ jobs:
           - os: ubuntu-22.04
           - os: macos-11
           - os: macos-12
+          - os: macos-13
 
     runs-on: ${{matrix.os}}
 
@@ -365,6 +383,7 @@ jobs:
           - os: ubuntu-22.04
           - os: macos-11
           - os: macos-12
+          - os: macos-13
 
     runs-on: ${{matrix.os}}
 

doc/describe/changes.adoc

@@ -8,6 +8,11 @@ https://www.boost.org/LICENSE_1_0.txt
 # Revision History
 :idprefix:
 
+## Changes in Boost 1.84.0
+
+* Added an overload of `enum_from_string` that takes a string view, to avoid
+  the need for null termination.
+
 ## Changes in Boost 1.81.0
 
 * To allow the inclusion of `enumerators.hpp`, `bases.hpp`, and `members.hpp`

doc/describe/reference.adoc

@@ -362,6 +362,7 @@ namespace boost {
 namespace describe {
 
 template<class E> bool enum_from_string( char const * name, E & e ) noexcept;
+template<class S, class E> bool enum_from_string( S const & name, E & e ) noexcept;
 
 } }
 ```
@@ -372,6 +373,11 @@ The function `enum_from_string` assigns to `e` the enumerator value correspondin
 to `name` and returns `true`. `E` must be a described enumeration type. If `name`
 does not correspond to one of the described values, the function returns `false`.
 
+The second overload only participates in overload resolution when `S` is a
+string-like type such as `std::string` or `std::string_view`. String-like types
+are recognized by the presence of nested `value_type` and `traits_type` typedefs
+and are expected to have a non-throwing `operator==` taking `char const*`.
+
 ## <boost/describe/operators.hpp>
 
 ```

example/json_rpc.cpp

@@ -80,6 +80,6 @@ BOOST_DESCRIBE_STRUCT(Object, (), (greet, add))
 int main()
 {
     Object obj;
-    std::cout << call( obj, "greet", { "world" } ) << std::endl;
-    std::cout << call( obj, "add", { 1, 2 } ) << std::endl;
+    std::cout << call( obj, "greet", {{ "world" }} ) << std::endl;
+    std::cout << call( obj, "add", {{ 1, 2 }} ) << std::endl;
 }

include/boost/describe/enum_from_string.hpp

@@ -12,6 +12,7 @@
 #include <boost/describe/enumerators.hpp>
 #include <boost/mp11/algorithm.hpp>
 #include <cstring>
+#include <type_traits>
 
 #if defined(_MSC_VER) && _MSC_VER == 1900
 # pragma warning(push)
@@ -41,6 +42,29 @@ bool enum_from_string( char const* name, E& e ) noexcept
     return found;
 }
 
+template<class S, class E, class De = describe_enumerators<E>,
+    class En = std::enable_if_t<
+        std::is_same<typename S::value_type, char>::value &&
+        std::is_same<typename S::traits_type::char_type, char>::value
+    >
+>
+bool enum_from_string( S const& name, E& e ) noexcept
+{
+    bool found = false;
+
+    mp11::mp_for_each<De>([&](auto D){
+
+        if( !found && name == D.name )
+        {
+            found = true;
+            e = D.value;
+        }
+
+    });
+
+    return found;
+}
+
 } // namespace describe
 } // namespace boost
 

test/Jamfile

@@ -78,6 +78,8 @@ run pedantic_bases_test.cpp
 run pedantic_members_test.cpp
   : : : <warnings>pedantic ;
 
+run enum_from_string_test2.cpp ;
+
 # examples
 
 obj describe_cxx14 : describe_cxx14.cpp ;
@@ -86,7 +88,7 @@ explicit describe_cxx14 ;
 local CXX14 = [ check-target-builds describe_cxx14 describe_cxx14 : : <build>no ] "<toolset>msvc-14.0:<cxxflags>-wd4100" ;
 
 local JSON = <library>/boost//json/<warnings>off "<toolset>msvc-14.2:<cxxflags>-wd5104" ;
-local SERIALIZATION = <library>/boost//serialization/<warnings>off "-<toolset>clang:<warnings-as-errors>on" ;
+local SERIALIZATION = <library>/boost//serialization/<warnings>off "-<toolset>gcc:<warnings-as-errors>on" "-<toolset>clang:<warnings-as-errors>on" ;
 
 run ../example/printing_enums_ct.cpp : : : $(CXX14) ;
 run ../example/printing_enums_rt.cpp : : : $(CXX14) ;

test/enum_from_string_test2.cpp

@@ -0,0 +1,78 @@
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/enum_from_string.hpp>
+#include <boost/describe/enum.hpp>
+#include <boost/core/detail/string_view.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <boost/config.hpp>
+
+#if !defined(BOOST_DESCRIBE_CXX14)
+
+#include <boost/config/pragma_message.hpp>
+
+BOOST_PRAGMA_MESSAGE("Skipping test because C++14 is not available")
+int main() {}
+
+#else
+
+enum E1 { v101 = 101, v102 = 102 };
+BOOST_DESCRIBE_ENUM(E1, v101, v102)
+
+enum class E2 { v201 = 201, v202 = 202 };
+BOOST_DESCRIBE_ENUM(E2, v201, v202)
+
+BOOST_DEFINE_ENUM(E3, v301, v302)
+BOOST_DEFINE_ENUM_CLASS(E4, v401, v402)
+
+template<class St> void test()
+{
+    using boost::describe::enum_from_string;
+
+    {
+        E1 w{};
+        BOOST_TEST( enum_from_string( St( "v101" ), w ) ) && BOOST_TEST_EQ( w, v101 );
+        BOOST_TEST( enum_from_string( St( "v102" ), w ) ) && BOOST_TEST_EQ( w, v102 );
+        BOOST_TEST_NOT( enum_from_string( St( "v103" ), w ) );
+    }
+
+    {
+        E2 w{};
+        BOOST_TEST( enum_from_string( St( "v201" ), w ) ) && BOOST_TEST_EQ( (int)w, (int)E2::v201 );
+        BOOST_TEST( enum_from_string( St( "v202" ), w ) ) && BOOST_TEST_EQ( (int)w, (int)E2::v202 );
+        BOOST_TEST_NOT( enum_from_string( St( "v203" ), w ) );
+    }
+
+    {
+        E3 w{};
+        BOOST_TEST( enum_from_string( St( "v301" ), w ) ) && BOOST_TEST_EQ( w, v301 );
+        BOOST_TEST( enum_from_string( St( "v302" ), w ) ) && BOOST_TEST_EQ( w, v302 );
+        BOOST_TEST_NOT( enum_from_string( St( "v303" ), w ) );
+    }
+
+    {
+        E4 w{};
+        BOOST_TEST( enum_from_string( St( "v401" ), w ) ) && BOOST_TEST_EQ( (int)w, (int)E4::v401 );
+        BOOST_TEST( enum_from_string( St( "v402" ), w ) ) && BOOST_TEST_EQ( (int)w, (int)E4::v402 );
+        BOOST_TEST_NOT( enum_from_string( St( "v403" ), w ) );
+    }
+}
+
+#if !defined(BOOST_NO_CXX17_HDR_STRING_VIEW)
+# include <string_view>
+#endif
+
+int main()
+{
+    test<std::string>();
+    test<boost::core::string_view>();
+
+#if !defined(BOOST_NO_CXX17_HDR_STRING_VIEW)
+    test<std::string_view>();
+#endif
+
+    return boost::report_errors();
+}
+
+#endif // !defined(BOOST_DESCRIBE_CXX14)