From 4c982b2ffe99f5dee70657424161de9541e00a21 Mon Sep 17 00:00:00 2001
From: Stanislaw Halik <sthalik@misaki.pl>
Date: Sat, 29 Oct 2022 16:49:12 +0200
Subject: serialize: use std::bit_cast

---
 serialize/binary-reader.inl | 48 ++++++++++-----------------------------------
 1 file changed, 10 insertions(+), 38 deletions(-)

(limited to 'serialize/binary-reader.inl')

diff --git a/serialize/binary-reader.inl b/serialize/binary-reader.inl
index 0c5b8531..b190f463 100644
--- a/serialize/binary-reader.inl
+++ b/serialize/binary-reader.inl
@@ -16,24 +16,16 @@ constexpr binary_reader<It>::binary_reader(It begin, It end) noexcept :
 {}
 
 template<string_input_iterator It>
-template<std::floating_point T>
-constexpr value_u binary_reader<It>::read_u() noexcept
+template<serializable T>
+constexpr T binary_reader<It>::read() noexcept
 {
-    value_u buf;
-    static_assert(sizeof(T) <= sizeof(buf));
-    fm_assert(std::distance(it, end) >= sizeof(T));
-    num_bytes_read += sizeof(T);
-    for (int i = 0; i < sizeof(T); i++)
-        buf.bytes[i] = *it++;
-    return buf;
-}
-
-template<string_input_iterator It>
-template<typename T>
-T binary_reader<It>::read() noexcept
-{
-    value_u buf = read_u<T>();
-    return *reinterpret_cast<T*>(buf.bytes);
+    constexpr std::size_t N = sizeof(T);
+    fm_assert((std::ptrdiff_t)N <= std::distance(it, end));
+    num_bytes_read += N;
+    char buf[N];
+    for (std::size_t i = 0; i < N; i++)
+        buf[i] = *it++;
+    return maybe_byteswap(std::bit_cast<T, decltype(buf)>(buf));
 }
 
 template<string_input_iterator It>
@@ -56,26 +48,6 @@ constexpr void binary_reader<It>::assert_end() noexcept
     fm_assert(it == end);
 }
 
-template<string_input_iterator It>
-template<integer T>
-constexpr value_u binary_reader<It>::read_u() noexcept
-{
-    value_u buf;
-    if (std::is_constant_evaluated())
-        for (std::size_t i = 0; i < std::size(buf.bytes); i++)
-            buf.bytes[i] = 0;
-    static_assert(sizeof(T) <= sizeof(buf));
-    fm_assert((std::ptrdiff_t)sizeof(T) <= std::distance(it, end));
-    num_bytes_read += sizeof(T);
-    if constexpr(std::endian::native == std::endian::big)
-        for (int i = sizeof(T) - 1; i >= 0; i--)
-            buf.bytes[i] = *it++;
-    else
-        for (std::size_t i = 0; i < sizeof(T); i++)
-            buf.bytes[i] = *it++;
-    return buf;
-}
-
 template<string_input_iterator It, serializable T>
 binary_reader<It>& operator>>(binary_reader<It>& reader, T& x) noexcept
 {
@@ -85,7 +57,7 @@ binary_reader<It>& operator>>(binary_reader<It>& reader, T& x) noexcept
 
 template<string_input_iterator It>
 template<std::size_t MAX>
-auto binary_reader<It>::read_asciiz_string() noexcept
+constexpr auto binary_reader<It>::read_asciiz_string() noexcept
 {
     static_assert(MAX > 0);
 
-- 
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