Issue #20614 has been updated by akr (Akira Tanaka). You can use RbConfig::SIZEOF to query the size of a C type. ``` % ruby -v -rrbconfig/sizeof -e 'pp RbConfig::SIZEOF' ruby 3.4.0dev (2024-05-16T19:35:22Z master 854cbbd5a9) [x86_64-linux] {"int"=>4, "short"=>2, "long"=>8, "long long"=>8, "__int128"=>16, "off_t"=>8, "void*"=>8, "float"=>4, "double"=>8, "time_t"=>8, "clock_t"=>8, "size_t"=>8, "ptrdiff_t"=>8, "dev_t"=>8, "int8_t"=>1, "uint8_t"=>1, "int16_t"=>2, "uint16_t"=>2, "int32_t"=>4, "uint32_t"=>4, "int64_t"=>8, "uint64_t"=>8, "int128_t"=>16, "uint128_t"=>16, "intptr_t"=>8, "uintptr_t"=>8, "ssize_t"=>8, "int_least8_t"=>1, "int_least16_t"=>2, "int_least32_t"=>4, "int_least64_t"=>8, "int_fast8_t"=>1, "int_fast16_t"=>8, "int_fast32_t"=>8, "int_fast64_t"=>8, "intmax_t"=>8, "sig_atomic_t"=>4, "wchar_t"=>4, "wint_t"=>4, "wctrans_t"=>8, "wctype_t"=>8, "_Bool"=>1, "long double"=>16, "float _Complex"=>8, "double _Complex"=>16, "long double _Complex"=>32, "__float128"=>16, "_Decimal32"=>4, "_Decimal64"=>8, "_Decimal128"=>16, "__float80"=>16} ``` ---------------------------------------- Bug #20614: Integer#size returns incorrect values on 64-bit Windows https://bugs.ruby-lang.org/issues/20614#change-109033 * Author: surusek (Łukasz Sur) * Status: Open * ruby -v: ruby 3.4.0dev (2024-07-08T11:00:01Z master 02c4f0c89d [x64-mswin64_140] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- According to the ruby/spec, `0.size` should return size of the machine word in bytes, but on x64-mswin64_140 (both release 3.3.3 and git revision 02c4f0c89d) it doesn't. Following example: ``` ruby a, b = 0.size, [0].pack('J').length puts a, b ``` should print two `8`s, but on x64-mswin64_140, a is `4`. Issue is most likely caused by use of `long` instead of `SIGNED_VALUE` in internal/fixnum.h and `fix_size` function in numeric.c, because on Windows, `long` is always a 32-bit number. -- https://bugs.ruby-lang.org/