Better decimal to float accuracy

2026-02-20 02:42:21 +00:00 · 2020-10-09 10:22:59 -07:00
parent 844851c6ab
commit 18a50dae83
1 changed files with 7 additions and 6 deletions
--- a/include/boost/json/basic_parser_impl.hpp
+++ b/include/boost/json/basic_parser_impl.hpp
@@ -138,13 +138,14 @@ dec_to_float(
    std::int32_t e,
    bool neg) noexcept
 {
+    auto x =
+        static_cast<double>(m);
    if(neg)
-        return (-static_cast<
-            double>(m)) *
-            pow10(e);
-    return (static_cast<
-        double>(m)) *
-        pow10(e);
+        x = -x;
+    if(e < -307)
+        return x * 1e-307 *
+            pow10(e+307);
+    return x * pow10(e);
 }

 inline