small interface fix and adaptations to current boost develop

.travis.yml

@@ -34,8 +34,10 @@ matrix:
         # ignore optional dependencies not currently supported by the cmake build
         - python tools/boostdep/depinst/depinst.py --git_args "--depth 5 --jobs 3" histogram -N accumulators -N range -N serialization -N units
 
-        # WORKAROUND: throw_exception tests have dependencies that depinst.py misses
+        # WORKAROUND: some external tests have extra dependencies that depinst.py misses
         - python tools/boostdep/depinst/depinst.py --git_args "--depth 5 --jobs 3" throw_exception
+        - python tools/boostdep/depinst/depinst.py --git_args "--depth 5 --jobs 3" smart_ptr
+        - python tools/boostdep/depinst/depinst.py --git_args "--depth 5 --jobs 3" move
 
       script:
         mkdir build && cd build &&

include/boost/histogram/axis/traits.hpp

@@ -15,12 +15,12 @@
 #include <boost/histogram/detail/static_if.hpp>
 #include <boost/histogram/detail/try_cast.hpp>
 #include <boost/histogram/detail/type_name.hpp>
+#include <boost/histogram/detail/variant2_with_warnings_disabled.hpp>
 #include <boost/histogram/fwd.hpp>
 #include <boost/mp11/algorithm.hpp>
 #include <boost/mp11/list.hpp>
 #include <boost/mp11/utility.hpp>
 #include <boost/throw_exception.hpp>
-#include <boost/variant2/variant.hpp>
 #include <stdexcept>
 #include <string>
 #include <utility>

include/boost/histogram/axis/variant.hpp

@@ -14,11 +14,11 @@
 #include <boost/histogram/detail/relaxed_equal.hpp>
 #include <boost/histogram/detail/static_if.hpp>
 #include <boost/histogram/detail/type_name.hpp>
+#include <boost/histogram/detail/variant2_with_warnings_disabled.hpp>
 #include <boost/histogram/detail/variant_proxy.hpp>
 #include <boost/mp11/algorithm.hpp> // mp_contains
 #include <boost/mp11/list.hpp>      // mp_first
 #include <boost/throw_exception.hpp>
-#include <boost/variant2/variant.hpp>
 #include <stdexcept>
 #include <type_traits>
 #include <utility>

include/boost/histogram/detail/detect.hpp

@@ -11,11 +11,18 @@
 #include <boost/mp11/algorithm.hpp>
 #include <boost/mp11/function.hpp>
 #include <boost/mp11/utility.hpp>
-#include <boost/variant2/variant.hpp>
 #include <iterator>
 #include <tuple>
 #include <type_traits>
 
+// forward declaration
+namespace boost {
+namespace variant2 {
+template <class...>
+class variant;
+} // namespace variant2
+} // namespace boost
+
 namespace boost {
 namespace histogram {
 namespace detail {

include/boost/histogram/detail/fill_n.hpp

@@ -19,12 +19,12 @@
 #include <boost/histogram/detail/optional_index.hpp>
 #include <boost/histogram/detail/span.hpp>
 #include <boost/histogram/detail/static_if.hpp>
+#include <boost/histogram/detail/variant2_with_warnings_disabled.hpp>
 #include <boost/histogram/fwd.hpp>
 #include <boost/mp11/algorithm.hpp>
 #include <boost/mp11/bind.hpp>
 #include <boost/mp11/utility.hpp>
 #include <boost/throw_exception.hpp>
-#include <boost/variant2/variant.hpp>
 #include <stdexcept>
 #include <type_traits>
 #include <utility>

include/boost/histogram/detail/span.hpp

@@ -7,8 +7,19 @@
 #ifndef BOOST_HISTOGRAM_DETAIL_SPAN_HPP
 #define BOOST_HISTOGRAM_DETAIL_SPAN_HPP
 
-#if __cpp_constexpr >= 201603 && __cpp_deduction_guides >= 201703 && \
-    __cpp_lib_nonmember_container_access >= 201411 && __has_include(<span>)
+#ifdef __has_include
+#if __has_include(<version>)
+#include <version>
+#ifdef __cpp_lib_span
+#if __cpp_lib_span >= 201902
+#define BOOST_HISTOGRAM_DETAIL_HAS_STD_SPAN
+#endif
+#endif
+#endif
+#endif
+
+#ifdef BOOST_HISTOGRAM_DETAIL_HAS_STD_SPAN
+
 #include <span>
 
 namespace boost {

include/boost/histogram/detail/variant2_with_warnings_disabled.hpp

@@ -0,0 +1,20 @@
+// Copyright 2019 Hans Dembinski
+//
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt
+// or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_HISTOGRAM_DETAIL_VARIANT2_WITH_WARNINGS_DISABLED_HPP
+#define BOOST_HISTOGRAM_DETAIL_VARIANT2_WITH_WARNINGS_DISABLED_HPP
+
+#include <boost/config/workaround.hpp>
+#if BOOST_WORKAROUND(BOOST_GCC, >= 5)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wextra"
+#endif
+#include <boost/variant2/variant.hpp>
+#if BOOST_WORKAROUND(BOOST_GCC, >= 5)
+#pragma GCC diagnostic pop
+#endif
+
+#endif

include/boost/histogram/histogram.hpp

@@ -489,10 +489,8 @@ public:
   }
 
   /// Multiply all values with a scalar.
-  template <class V = value_type>
-  std::enable_if_t<(detail::has_operator_rmul<V, double>::value &&
-                    detail::has_operator_rmul<storage_type, double>::value == true),
-                   histogram&>
+  template <class S = storage_type>
+  std::enable_if_t<(detail::has_operator_rmul<S, double>::value == true), histogram&>
   operator*=(const double x) {
     // use special implementation of scaling if available
     storage_ *= x;
@@ -500,10 +498,8 @@ public:
   }
 
   /// Multiply all values with a scalar.
-  template <class V = value_type>
-  std::enable_if_t<(detail::has_operator_rmul<V, double>::value &&
-                    detail::has_operator_rmul<storage_type, double>::value == false),
-                   histogram&>
+  template <class S = storage_type>
+  std::enable_if_t<(detail::has_operator_rmul<S, double>::value == false), histogram&>
   operator*=(const double x) {
     // generic implementation of scaling
     for (auto&& si : storage_) si *= x;

test/histogram_fill_test.cpp

@@ -14,12 +14,12 @@
 #include <boost/histogram/axis/category.hpp>
 #include <boost/histogram/axis/integer.hpp>
 #include <boost/histogram/axis/ostream.hpp>
+#include <boost/histogram/detail/variant2_with_warnings_disabled.hpp>
 #include <boost/histogram/histogram.hpp>
 #include <boost/histogram/literals.hpp>
 #include <boost/histogram/make_histogram.hpp>
 #include <boost/histogram/ostream.hpp>
 #include <boost/histogram/storage_adaptor.hpp>
-#include <boost/variant2/variant.hpp>
 #include <random>
 #include <sstream>
 #include <stdexcept>
@@ -92,7 +92,7 @@ void run_tests(const std::vector<int>& x, const std::vector<int>& y,
     h(1);
     for (auto&& xi : x) h(xi);
     // uses variant
-    boost::variant2::variant<int, std::vector<int>, std::string> v[1];
+    variant<int, std::vector<int>, std::string> v[1];
     v[0] = 1;
     h2.fill(v);
     v[0] = x;