MSVC fixes (#2304)

* MSVC fixes

* Update dragonbox.hpp

* More MSVC warning fixes

* More MSVC fixes

* avoid MSVC unreachable code warnings

* #pragma warning(push/disable/pop)

* fix MSVC

* more msvc fixes

* msvc fixes

* more warning fixes

* Update value_based_skip_test.cpp

* increase msvc workflow timeout

* Add 2 minute timeouts for msvc tests

* longer timeouts

* fix temp_file_path for windows

Author: stephenberry

.github/workflows/msvc.yml

@@ -23,7 +23,7 @@ env:
 jobs:
   build:
     runs-on: windows-2025-vs2026
-    timeout-minutes: 10
+    timeout-minutes: 30
 
     strategy:
       matrix:
@@ -40,4 +40,4 @@ jobs:
 
     - name: Test
       working-directory: build
-      run: ctest --build-config ${{env.BUILD_TYPE}}
+      run: ctest --build-config ${{env.BUILD_TYPE}} --timeout 300

include/glaze/beve/read.hpp

@@ -1619,6 +1619,10 @@ namespace glz
       }
    };
 
+#if defined(_MSC_VER)
+#pragma warning(push)
+#pragma warning(disable : 4702) // unreachable code from if constexpr
+#endif
    template <class T>
       requires((glaze_object_t<T> || reflectable<T>) && not custom_read<T>)
    struct from<BEVE, T> final
@@ -1693,6 +1697,9 @@ namespace glz
          ++it;
 
          static constexpr auto N = reflect<T>::size;
+         if constexpr (N == 0) {
+            (void)value;
+         }
 
          static constexpr bit_array<N> all_fields = [] {
             bit_array<N> arr{};
@@ -1825,6 +1832,9 @@ namespace glz
          }
       }
    };
+#if defined(_MSC_VER)
+#pragma warning(pop)
+#endif
 
    template <class T>
       requires glaze_array_t<T>

include/glaze/beve/write.hpp

@@ -1341,6 +1341,11 @@ namespace glz
             }
 
             // Second pass: write members
+
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable : 4702) // unreachable code from if constexpr
+#endif
             for_each<N>([&]<size_t I>() {
                if (bool(ctx.error)) [[unlikely]] {
                   return;
@@ -1403,6 +1408,9 @@ namespace glz
                   }
                }
             });
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
          }
          else {
             // Static path: use compile-time count for better performance

include/glaze/cbor/read.hpp

@@ -1306,6 +1306,10 @@ namespace glz
       }
    };
 
+#if defined(_MSC_VER)
+#pragma warning(push)
+#pragma warning(disable : 4702) // unreachable code from if constexpr
+#endif
    // Glaze objects (structs with reflection)
    template <class T>
       requires((glaze_object_t<T> || reflectable<T>) && !custom_read<T>)
@@ -1334,6 +1338,9 @@ namespace glz
          }
 
          static constexpr auto N = reflect<T>::size;
+         if constexpr (N == 0) {
+            (void)value;
+         }
 
          uint64_t n_keys;
          if (additional_info == info::indefinite) {
@@ -1448,6 +1455,9 @@ namespace glz
          }
       }
    };
+#if defined(_MSC_VER)
+#pragma warning(pop)
+#endif
 
    // Tuples
    template <class T>

include/glaze/csv/read.hpp

@@ -493,6 +493,10 @@ namespace glz
       using Row = typename T::value_type;
       using Value = typename Row::value_type;
 
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable : 4702) // unreachable code from if constexpr
+#endif
       template <auto Opts, class It>
       static void op(auto&& value, is_context auto&& ctx, It&& it, auto end)
       {
@@ -796,6 +800,9 @@ namespace glz
             }
          }
       }
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
    };
 
    template <char delim>

include/glaze/json/read.hpp

@@ -3770,11 +3770,11 @@ namespace glz
                                  constexpr auto variant_size = std::variant_size_v<T>;
                                  if constexpr (ids_size < variant_size) {
                                     // Use the first unlabeled type as the default
-                                    const auto type_index = ids_size;
+                                    const auto default_type_index = ids_size;
 
                                     it = start; // we restart our object parsing now that we know the target type
-                                    tag_specified_index = type_index; // Store the default type index
-                                    if (value.index() != type_index) emplace_runtime_variant(value, type_index);
+                                    tag_specified_index = default_type_index; // Store the default type index
+                                    if (value.index() != default_type_index) emplace_runtime_variant(value, default_type_index);
                                     std::visit(
                                        [&](auto&& v) {
                                           using V = std::decay_t<decltype(v)>;

include/glaze/json/write.hpp

@@ -544,7 +544,10 @@ namespace glz
    constexpr bool write_can_error()
    {
       using V = std::remove_cvref_t<T>;
-      if constexpr (requires {
+      if constexpr (always_skipped<V>) {
+         return false; // hidden/skip types are never written
+      }
+      else if constexpr (requires {
                        { to<JSON, V>::can_error } -> std::convertible_to<bool>;
                     }) {
          return to<JSON, V>::can_error;

include/glaze/msgpack/write.hpp

@@ -708,6 +708,10 @@ namespace glz
       }
    };
 
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable : 4702) // unreachable code from if constexpr
+#endif
    template <writable_array_t T>
    struct to<MSGPACK, T>
    {
@@ -740,6 +744,9 @@ namespace glz
             }
          }
       }
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
    };
 
    template <>

include/glaze/net/http_server.hpp

@@ -2146,7 +2146,13 @@ namespace glz
          auto time_t_now = std::chrono::system_clock::to_time_t(now);
 
          char buf[100];
+#ifdef _MSC_VER
+         std::tm tm_buf;
+         gmtime_s(&tm_buf, &time_t_now);
+         std::strftime(buf, sizeof(buf), "%a, %d %b %Y %H:%M:%S GMT", &tm_buf);
+#else
          std::strftime(buf, sizeof(buf), "%a, %d %b %Y %H:%M:%S GMT", std::gmtime(&time_t_now));
+#endif
 
          return buf;
       }

include/glaze/net/websocket_connection.hpp

@@ -153,8 +153,8 @@ namespace glz
             size_t i = 0;
             size_t j = (context->count[0] >> 3) & 63;
 
-            if ((context->count[0] += uint32_t(len << 3)) < (len << 3)) context->count[1]++;
-            context->count[1] += (len >> 29);
+            if ((context->count[0] += uint32_t(len << 3)) < uint32_t(len << 3)) context->count[1]++;
+            context->count[1] += uint32_t(len >> 29);
 
             if ((j + len) > 63) {
                std::memcpy(&context->buffer[j], data, (i = 64 - j));