Merge branch 'json-view/23-zmij' into json-view/24-view-token-digits

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

include/nlohmann/detail/conversions/to_chars.hpp

@@ -983,7 +983,8 @@ inline void shortest_digits(char* buf, int& len, int& decimal_exponent, double v
     std::size_t n = digits.size();
     while (d.significand >= 100)
     {
-        const auto i = static_cast<std::size_t>(d.significand % 100) * 2;
+        const std::uint64_t two_digits = d.significand % 100; // a variable: GCC calls a cast of the remainder useless where std::uint64_t is std::size_t
+        const auto i = static_cast<std::size_t>(two_digits) * 2;
         d.significand /= 100;
         n -= 2;
         digits[n] = pairs[i];

include/nlohmann/detail/view/builder.hpp

@@ -202,8 +202,9 @@ class builder
     {
         const std::uint64_t done = static_cast<std::uint64_t>(at - b) + 1;
         const std::uint64_t guess = static_cast<std::uint64_t>(n) * static_cast<std::uint64_t>(e - b + 1) / done;
+        const std::uint64_t grown = guess + (guess / 4) + 64; // a variable: GCC calls a cast of the sum useless where std::uint64_t is std::size_t
         doc.tape_size = n;
-        doc.reserve((std::max)(static_cast<std::size_t>(guess + (guess / 4) + 64), n + (n / 2) + 64));
+        doc.reserve((std::max)(static_cast<std::size_t>(grown), n + (n / 2) + 64));
         return doc.tape;
     }
 
@@ -425,6 +426,14 @@ class builder
         return w;
     }
 
+    /// a compile-time option as a runtime condition: testing the template
+    /// argument directly makes a condition like `TrailingCommas && c == ']'`
+    /// constant when the option is off, which MSVC reports as C4127
+    static NLOHMANN_VIEW_ALWAYS_INLINE bool enabled(bool option) noexcept
+    {
+        return option;
+    }
+
     /// The parse state and the parser proper. The cursor is a local object of
     /// run() whose address never escapes (everything it calls out of line is a
     /// member of the builder and gets the positions it needs), so that the
@@ -554,7 +563,7 @@ arr_next:
                 {
                     return false;
                 }
-                if (TrailingCommas && cur() == ']')
+                if (enabled(TrailingCommas) && cur() == ']')
                 {
                     ++p;
                     goto close_container;
@@ -621,7 +630,7 @@ obj_next:
                 {
                     return false;
                 }
-                if (TrailingCommas && cur() == '}')
+                if (enabled(TrailingCommas) && cur() == '}')
                 {
                     ++p;
                     goto close_object;
@@ -771,7 +780,7 @@ indent_done:
                 {
                     ++p;
                 }
-                if (Comments && cur() == '/')
+                if (enabled(Comments) && cur() == '/')
                 {
                     const unsigned char* const q = cold.comment(p);
                     if (q == nullptr)

include/nlohmann/detail/view/object_index.hpp

@@ -71,7 +71,8 @@ inline void build_object_index(document_data& d, node* obj)
     for (const node* k = document_data::first_child(obj), *end = document_data::child_end(obj); k != end; k = document_data::after(k + 1))
     {
         const char* const key = d.str(*k);
-        std::size_t i = static_cast<std::size_t>(key_hash(key, k->len)) & mask;
+        const std::uint64_t hash = key_hash(key, k->len); // (a cast of the call would be useless where std::uint64_t is std::size_t)
+        std::size_t i = static_cast<std::size_t>(hash) & mask;
         bool duplicate = false;
         while (slots[i] != 0)
         {
@@ -107,7 +108,8 @@ inline const node* find_indexed(const document_data& d, const node* obj, const c
 {
     const document_data::object_index& ix = d.indexes[obj->extra - 1u];
     const std::uint32_t* const slots = d.index_slots.data() + ix.start;
-    std::size_t i = static_cast<std::size_t>(key_hash(key, n)) & ix.mask;
+    const std::uint64_t hash = key_hash(key, n); // (a cast of the call would be useless where std::uint64_t is std::size_t)
+    std::size_t i = static_cast<std::size_t>(hash) & ix.mask;
     for (;;)
     {
         const std::uint32_t s = slots[i];

include/nlohmann/detail/view/pointer.hpp

@@ -69,7 +69,7 @@ index_status array_index(const StringType& s, std::size_t& idx) noexcept
         }
         v = (v * 10) + d;
     }
-    if (v >= static_cast<std::uint64_t>((std::numeric_limits<std::size_t>::max)()))
+    if (v >= (std::numeric_limits<std::size_t>::max)()) // (std::size_t converts to std::uint64_t implicitly)
     {
         return index_status::too_large;
     }