An idea of redesign Zig's std.math.big.int

bigint.zig

const std = @import("std");
const testing = std.testing;

pub const Limb = u64;

pub const Metadata = packed struct {
    // positive is set as true for n >= 0, false for n < 0.
    positive: bool,
    len: u63,
};

pub const Const = struct {
    /// Raw digits. These are:
    ///
    /// * Little-endian ordered
    /// * limbs.len >= 1
    /// * Zero is represented as limbs.len == 1 with limbs[0] == 0.
    ///
    /// Accessing limbs directly should be avoided.
    limbs: []const Limb,
    metadata: Metadata,

    pub inline fn capacity(self: Const) u63 {
        return @intCast(u63, self.limbs.len);
    }

    pub inline fn len(self: Const) u63 {
        return self.limbs.metadata.len;
    }

    pub inline fn positive(self: Const) bool {
        return self.limbs.metadata.positive;
    }
};

pub const Mutable = struct {
    /// Raw digits. These are:
    ///
    /// * Little-endian ordered
    /// * limbs.len >= 1
    /// * Zero is represented as limbs.len == 1 with limbs[0] == 0.
    ///
    /// Accessing limbs directly should be avoided.
    limbs: []Limb,
    metadata: Metadata,

    pub inline fn capacity(self: Mutable) u63 {
        return @intCast(u63, self.limbs.len);
    }

    pub inline fn len(self: Mutable) u63 {
        return self.limbs.metadata.len;
    }

    pub inline fn positive(self: Mutable) bool {
        return self.limbs.metadata.positive;
    }
};

pub const Managed = struct {
    /// Raw digits. These are:
    ///
    /// * Little-endian ordered
    /// * limbs.len >= 1
    /// * Zero is represented as limbs.len == 1 with limbs[0] == 0.
    ///
    /// Accessing limbs directly should be avoided.
    limbs: []Limb,
    metadata: Metadata,
    allocator: std.mem.Allocator,

    pub fn deinit(self: *Managed) void {
        self.allocator.free(self.limbs);
    }

    pub inline fn capacity(self: Managed) u63 {
        return @intCast(u63, self.limbs.len);
    }

    pub inline fn len(self: Managed) u63 {
        return self.limbs.metadata.len;
    }

    pub inline fn positive(self: Managed) bool {
        return self.limbs.metadata.positive;
    }
};

test "Const" {
    const c = Const{ .limbs = ([_]Limb{1})[0..], .metadata = .{ .positive = true, .len = 1 } };
    std.debug.print("c={any}\n", .{c});
}

test "Mutable" {
    var limbs = [_]Limb{1};
    const m = Mutable{ .limbs = limbs[0..], .metadata = .{ .positive = true, .len = 1 } };
    std.debug.print("m={any}\n", .{m});
}

test "Managed" {
    const allocator = testing.allocator;
    var m = blk: {
        var limbs = try allocator.alloc(Limb, 4);
        limbs[0] = 1;
        var i: usize = 1;
        while (i < limbs.len) : (i += 1) {
            limbs[i] = 0;
        }
        break :blk Managed{
            .limbs = limbs,
            .metadata = .{ .positive = true, .len = 1 },
            .allocator = allocator,
        };
    };
    defer m.deinit();
    std.debug.print("m={any}\n", .{m});
}

bigint_using_flexible_array.zig

const std = @import("std");
const testing = std.testing;

pub const Limb = u64;

pub const Const = packed struct {
    positive: bool,
    len: u63,
    /// Raw digits. These are:
    ///
    /// * Little-endian ordered
    /// * limbs.len >= 1
    /// * Zero is represented as limbs.len == 1 with limbs[0] == 0.
    ///
    /// Accessing limbs directly should be avoided.
    limbs: std.zig.c_translation.FlexibleArrayType(*const Const, Limb),
};

pub const Mutable = packed struct {
    positive: bool,
    len: u63,
    /// Raw digits. These are:
    ///
    /// * Little-endian ordered
    /// * limbs.len >= 1
    /// * Zero is represented as limbs.len == 1 with limbs[0] == 0.
    ///
    /// Accessing limbs directly should be avoided.
    limbs: std.zig.c_translation.FlexibleArrayType(*Mutable, Limb),
};

test "Const" {
    // We need to store limbs outside of Const after all.
    const limbs = [_]Limb{0};
    const c = Const{.positive = true, .len = 1, .limbs = limbs[0..]};
    std.debug.print("c={any}\n", .{c});
}

c_bigint.c

typedef struct st_bigint {
    unsigned long long positive: 1;
    unsigned long long len: 63;
    unsigned long long limbs[];
} bigint_t;

c_bigint.txt

zig translate-c c_bigint.c > c_bigint.zig

c_bigint.zig

pub const __builtin_bswap16 = @import("std").zig.c_builtins.__builtin_bswap16;
pub const __builtin_bswap32 = @import("std").zig.c_builtins.__builtin_bswap32;
pub const __builtin_bswap64 = @import("std").zig.c_builtins.__builtin_bswap64;
pub const __builtin_signbit = @import("std").zig.c_builtins.__builtin_signbit;
pub const __builtin_signbitf = @import("std").zig.c_builtins.__builtin_signbitf;
pub const __builtin_popcount = @import("std").zig.c_builtins.__builtin_popcount;
pub const __builtin_ctz = @import("std").zig.c_builtins.__builtin_ctz;
pub const __builtin_clz = @import("std").zig.c_builtins.__builtin_clz;
pub const __builtin_sqrt = @import("std").zig.c_builtins.__builtin_sqrt;
pub const __builtin_sqrtf = @import("std").zig.c_builtins.__builtin_sqrtf;
pub const __builtin_sin = @import("std").zig.c_builtins.__builtin_sin;
pub const __builtin_sinf = @import("std").zig.c_builtins.__builtin_sinf;
pub const __builtin_cos = @import("std").zig.c_builtins.__builtin_cos;
pub const __builtin_cosf = @import("std").zig.c_builtins.__builtin_cosf;
pub const __builtin_exp = @import("std").zig.c_builtins.__builtin_exp;
pub const __builtin_expf = @import("std").zig.c_builtins.__builtin_expf;
pub const __builtin_exp2 = @import("std").zig.c_builtins.__builtin_exp2;
pub const __builtin_exp2f = @import("std").zig.c_builtins.__builtin_exp2f;
pub const __builtin_log = @import("std").zig.c_builtins.__builtin_log;
pub const __builtin_logf = @import("std").zig.c_builtins.__builtin_logf;
pub const __builtin_log2 = @import("std").zig.c_builtins.__builtin_log2;
pub const __builtin_log2f = @import("std").zig.c_builtins.__builtin_log2f;
pub const __builtin_log10 = @import("std").zig.c_builtins.__builtin_log10;
pub const __builtin_log10f = @import("std").zig.c_builtins.__builtin_log10f;
pub const __builtin_abs = @import("std").zig.c_builtins.__builtin_abs;
pub const __builtin_fabs = @import("std").zig.c_builtins.__builtin_fabs;
pub const __builtin_fabsf = @import("std").zig.c_builtins.__builtin_fabsf;
pub const __builtin_floor = @import("std").zig.c_builtins.__builtin_floor;
pub const __builtin_floorf = @import("std").zig.c_builtins.__builtin_floorf;
pub const __builtin_ceil = @import("std").zig.c_builtins.__builtin_ceil;
pub const __builtin_ceilf = @import("std").zig.c_builtins.__builtin_ceilf;
pub const __builtin_trunc = @import("std").zig.c_builtins.__builtin_trunc;
pub const __builtin_truncf = @import("std").zig.c_builtins.__builtin_truncf;
pub const __builtin_round = @import("std").zig.c_builtins.__builtin_round;
pub const __builtin_roundf = @import("std").zig.c_builtins.__builtin_roundf;
pub const __builtin_strlen = @import("std").zig.c_builtins.__builtin_strlen;
pub const __builtin_strcmp = @import("std").zig.c_builtins.__builtin_strcmp;
pub const __builtin_object_size = @import("std").zig.c_builtins.__builtin_object_size;
pub const __builtin___memset_chk = @import("std").zig.c_builtins.__builtin___memset_chk;
pub const __builtin_memset = @import("std").zig.c_builtins.__builtin_memset;
pub const __builtin___memcpy_chk = @import("std").zig.c_builtins.__builtin___memcpy_chk;
pub const __builtin_memcpy = @import("std").zig.c_builtins.__builtin_memcpy;
pub const __builtin_expect = @import("std").zig.c_builtins.__builtin_expect;
pub const __builtin_nanf = @import("std").zig.c_builtins.__builtin_nanf;
pub const __builtin_huge_valf = @import("std").zig.c_builtins.__builtin_huge_valf;
pub const __builtin_inff = @import("std").zig.c_builtins.__builtin_inff;
pub const __builtin_isnan = @import("std").zig.c_builtins.__builtin_isnan;
pub const __builtin_isinf = @import("std").zig.c_builtins.__builtin_isinf;
pub const __builtin_isinf_sign = @import("std").zig.c_builtins.__builtin_isinf_sign;
pub const __has_builtin = @import("std").zig.c_builtins.__has_builtin;
pub const __builtin_assume = @import("std").zig.c_builtins.__builtin_assume;
pub const __builtin_unreachable = @import("std").zig.c_builtins.__builtin_unreachable;
pub const __builtin_constant_p = @import("std").zig.c_builtins.__builtin_constant_p;
pub const __builtin_mul_overflow = @import("std").zig.c_builtins.__builtin_mul_overflow; // a.c:2:24: warning: struct demoted to opaque type - has bitfield
pub const struct_st_bigint = opaque {};
pub const bigint_t = struct_st_bigint;
pub const __INTMAX_C_SUFFIX__ = @compileError("unable to translate macro: undefined identifier `L`"); // (no file):66:9
pub const __UINTMAX_C_SUFFIX__ = @compileError("unable to translate macro: undefined identifier `UL`"); // (no file):72:9
pub const __INT64_C_SUFFIX__ = @compileError("unable to translate macro: undefined identifier `L`"); // (no file):163:9
pub const __UINT32_C_SUFFIX__ = @compileError("unable to translate macro: undefined identifier `U`"); // (no file):185:9
pub const __UINT64_C_SUFFIX__ = @compileError("unable to translate macro: undefined identifier `UL`"); // (no file):193:9
pub const __seg_gs = @compileError("unable to translate macro: undefined identifier `__attribute__`"); // (no file):312:9
pub const __seg_fs = @compileError("unable to translate macro: undefined identifier `__attribute__`"); // (no file):313:9
pub const __llvm__ = @as(c_int, 1);
pub const __clang__ = @as(c_int, 1);
pub const __clang_major__ = @as(c_int, 13);
pub const __clang_minor__ = @as(c_int, 0);
pub const __clang_patchlevel__ = @as(c_int, 1);
pub const __clang_version__ = "13.0.1 (git@github.com:ziglang/zig-bootstrap.git 81f0e6c5b902ead84753490db4f0007d08df964a)";
pub const __GNUC__ = @as(c_int, 4);
pub const __GNUC_MINOR__ = @as(c_int, 2);
pub const __GNUC_PATCHLEVEL__ = @as(c_int, 1);
pub const __GXX_ABI_VERSION = @as(c_int, 1002);
pub const __ATOMIC_RELAXED = @as(c_int, 0);
pub const __ATOMIC_CONSUME = @as(c_int, 1);
pub const __ATOMIC_ACQUIRE = @as(c_int, 2);
pub const __ATOMIC_RELEASE = @as(c_int, 3);
pub const __ATOMIC_ACQ_REL = @as(c_int, 4);
pub const __ATOMIC_SEQ_CST = @as(c_int, 5);
pub const __OPENCL_MEMORY_SCOPE_WORK_ITEM = @as(c_int, 0);
pub const __OPENCL_MEMORY_SCOPE_WORK_GROUP = @as(c_int, 1);
pub const __OPENCL_MEMORY_SCOPE_DEVICE = @as(c_int, 2);
pub const __OPENCL_MEMORY_SCOPE_ALL_SVM_DEVICES = @as(c_int, 3);
pub const __OPENCL_MEMORY_SCOPE_SUB_GROUP = @as(c_int, 4);
pub const __PRAGMA_REDEFINE_EXTNAME = @as(c_int, 1);
pub const __VERSION__ = "Clang 13.0.1 (git@github.com:ziglang/zig-bootstrap.git 81f0e6c5b902ead84753490db4f0007d08df964a)";
pub const __OBJC_BOOL_IS_BOOL = @as(c_int, 0);
pub const __CONSTANT_CFSTRINGS__ = @as(c_int, 1);
pub const __clang_literal_encoding__ = "UTF-8";
pub const __clang_wide_literal_encoding__ = "UTF-32";
pub const __ORDER_LITTLE_ENDIAN__ = @as(c_int, 1234);
pub const __ORDER_BIG_ENDIAN__ = @as(c_int, 4321);
pub const __ORDER_PDP_ENDIAN__ = @as(c_int, 3412);
pub const __BYTE_ORDER__ = __ORDER_LITTLE_ENDIAN__;
pub const __LITTLE_ENDIAN__ = @as(c_int, 1);
pub const _LP64 = @as(c_int, 1);
pub const __LP64__ = @as(c_int, 1);
pub const __CHAR_BIT__ = @as(c_int, 8);
pub const __SCHAR_MAX__ = @as(c_int, 127);
pub const __SHRT_MAX__ = @as(c_int, 32767);
pub const __INT_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_int, 2147483647, .decimal);
pub const __LONG_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_long, 9223372036854775807, .decimal);
pub const __LONG_LONG_MAX__ = @as(c_longlong, 9223372036854775807);
pub const __WCHAR_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_int, 2147483647, .decimal);
pub const __WINT_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_uint, 4294967295, .decimal);
pub const __INTMAX_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_long, 9223372036854775807, .decimal);
pub const __SIZE_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_ulong, 18446744073709551615, .decimal);
pub const __UINTMAX_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_ulong, 18446744073709551615, .decimal);
pub const __PTRDIFF_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_long, 9223372036854775807, .decimal);
pub const __INTPTR_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_long, 9223372036854775807, .decimal);
pub const __UINTPTR_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_ulong, 18446744073709551615, .decimal);
pub const __SIZEOF_DOUBLE__ = @as(c_int, 8);
pub const __SIZEOF_FLOAT__ = @as(c_int, 4);
pub const __SIZEOF_INT__ = @as(c_int, 4);
pub const __SIZEOF_LONG__ = @as(c_int, 8);
pub const __SIZEOF_LONG_DOUBLE__ = @as(c_int, 16);
pub const __SIZEOF_LONG_LONG__ = @as(c_int, 8);
pub const __SIZEOF_POINTER__ = @as(c_int, 8);
pub const __SIZEOF_SHORT__ = @as(c_int, 2);
pub const __SIZEOF_PTRDIFF_T__ = @as(c_int, 8);
pub const __SIZEOF_SIZE_T__ = @as(c_int, 8);
pub const __SIZEOF_WCHAR_T__ = @as(c_int, 4);
pub const __SIZEOF_WINT_T__ = @as(c_int, 4);
pub const __SIZEOF_INT128__ = @as(c_int, 16);
pub const __INTMAX_TYPE__ = c_long;
pub const __INTMAX_FMTd__ = "ld";
pub const __INTMAX_FMTi__ = "li";
pub const __UINTMAX_TYPE__ = c_ulong;
pub const __UINTMAX_FMTo__ = "lo";
pub const __UINTMAX_FMTu__ = "lu";
pub const __UINTMAX_FMTx__ = "lx";
pub const __UINTMAX_FMTX__ = "lX";
pub const __INTMAX_WIDTH__ = @as(c_int, 64);
pub const __PTRDIFF_TYPE__ = c_long;
pub const __PTRDIFF_FMTd__ = "ld";
pub const __PTRDIFF_FMTi__ = "li";
pub const __PTRDIFF_WIDTH__ = @as(c_int, 64);
pub const __INTPTR_TYPE__ = c_long;
pub const __INTPTR_FMTd__ = "ld";
pub const __INTPTR_FMTi__ = "li";
pub const __INTPTR_WIDTH__ = @as(c_int, 64);
pub const __SIZE_TYPE__ = c_ulong;
pub const __SIZE_FMTo__ = "lo";
pub const __SIZE_FMTu__ = "lu";
pub const __SIZE_FMTx__ = "lx";
pub const __SIZE_FMTX__ = "lX";
pub const __SIZE_WIDTH__ = @as(c_int, 64);
pub const __WCHAR_TYPE__ = c_int;
pub const __WCHAR_WIDTH__ = @as(c_int, 32);
pub const __WINT_TYPE__ = c_uint;
pub const __WINT_WIDTH__ = @as(c_int, 32);
pub const __SIG_ATOMIC_WIDTH__ = @as(c_int, 32);
pub const __SIG_ATOMIC_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_int, 2147483647, .decimal);
pub const __CHAR16_TYPE__ = c_ushort;
pub const __CHAR32_TYPE__ = c_uint;
pub const __UINTMAX_WIDTH__ = @as(c_int, 64);
pub const __UINTPTR_TYPE__ = c_ulong;
pub const __UINTPTR_FMTo__ = "lo";
pub const __UINTPTR_FMTu__ = "lu";
pub const __UINTPTR_FMTx__ = "lx";
pub const __UINTPTR_FMTX__ = "lX";
pub const __UINTPTR_WIDTH__ = @as(c_int, 64);
pub const __FLT_DENORM_MIN__ = @as(f32, 1.40129846e-45);
pub const __FLT_HAS_DENORM__ = @as(c_int, 1);
pub const __FLT_DIG__ = @as(c_int, 6);
pub const __FLT_DECIMAL_DIG__ = @as(c_int, 9);
pub const __FLT_EPSILON__ = @as(f32, 1.19209290e-7);
pub const __FLT_HAS_INFINITY__ = @as(c_int, 1);
pub const __FLT_HAS_QUIET_NAN__ = @as(c_int, 1);
pub const __FLT_MANT_DIG__ = @as(c_int, 24);
pub const __FLT_MAX_10_EXP__ = @as(c_int, 38);
pub const __FLT_MAX_EXP__ = @as(c_int, 128);
pub const __FLT_MAX__ = @as(f32, 3.40282347e+38);
pub const __FLT_MIN_10_EXP__ = -@as(c_int, 37);
pub const __FLT_MIN_EXP__ = -@as(c_int, 125);
pub const __FLT_MIN__ = @as(f32, 1.17549435e-38);
pub const __DBL_DENORM_MIN__ = 4.9406564584124654e-324;
pub const __DBL_HAS_DENORM__ = @as(c_int, 1);
pub const __DBL_DIG__ = @as(c_int, 15);
pub const __DBL_DECIMAL_DIG__ = @as(c_int, 17);
pub const __DBL_EPSILON__ = 2.2204460492503131e-16;
pub const __DBL_HAS_INFINITY__ = @as(c_int, 1);
pub const __DBL_HAS_QUIET_NAN__ = @as(c_int, 1);
pub const __DBL_MANT_DIG__ = @as(c_int, 53);
pub const __DBL_MAX_10_EXP__ = @as(c_int, 308);
pub const __DBL_MAX_EXP__ = @as(c_int, 1024);
pub const __DBL_MAX__ = 1.7976931348623157e+308;
pub const __DBL_MIN_10_EXP__ = -@as(c_int, 307);
pub const __DBL_MIN_EXP__ = -@as(c_int, 1021);
pub const __DBL_MIN__ = 2.2250738585072014e-308;
pub const __LDBL_DENORM_MIN__ = @as(c_longdouble, 3.64519953188247460253e-4951);
pub const __LDBL_HAS_DENORM__ = @as(c_int, 1);
pub const __LDBL_DIG__ = @as(c_int, 18);
pub const __LDBL_DECIMAL_DIG__ = @as(c_int, 21);
pub const __LDBL_EPSILON__ = @as(c_longdouble, 1.08420217248550443401e-19);
pub const __LDBL_HAS_INFINITY__ = @as(c_int, 1);
pub const __LDBL_HAS_QUIET_NAN__ = @as(c_int, 1);
pub const __LDBL_MANT_DIG__ = @as(c_int, 64);
pub const __LDBL_MAX_10_EXP__ = @as(c_int, 4932);
pub const __LDBL_MAX_EXP__ = @as(c_int, 16384);
pub const __LDBL_MAX__ = @as(c_longdouble, 1.18973149535723176502e+4932);
pub const __LDBL_MIN_10_EXP__ = -@as(c_int, 4931);
pub const __LDBL_MIN_EXP__ = -@as(c_int, 16381);
pub const __LDBL_MIN__ = @as(c_longdouble, 3.36210314311209350626e-4932);
pub const __POINTER_WIDTH__ = @as(c_int, 64);
pub const __BIGGEST_ALIGNMENT__ = @as(c_int, 16);
pub const __WINT_UNSIGNED__ = @as(c_int, 1);
pub const __INT8_TYPE__ = i8;
pub const __INT8_FMTd__ = "hhd";
pub const __INT8_FMTi__ = "hhi";
pub const __INT8_C_SUFFIX__ = "";
pub const __INT16_TYPE__ = c_short;
pub const __INT16_FMTd__ = "hd";
pub const __INT16_FMTi__ = "hi";
pub const __INT16_C_SUFFIX__ = "";
pub const __INT32_TYPE__ = c_int;
pub const __INT32_FMTd__ = "d";
pub const __INT32_FMTi__ = "i";
pub const __INT32_C_SUFFIX__ = "";
pub const __INT64_TYPE__ = c_long;
pub const __INT64_FMTd__ = "ld";
pub const __INT64_FMTi__ = "li";
pub const __UINT8_TYPE__ = u8;
pub const __UINT8_FMTo__ = "hho";
pub const __UINT8_FMTu__ = "hhu";
pub const __UINT8_FMTx__ = "hhx";
pub const __UINT8_FMTX__ = "hhX";
pub const __UINT8_C_SUFFIX__ = "";
pub const __UINT8_MAX__ = @as(c_int, 255);
pub const __INT8_MAX__ = @as(c_int, 127);
pub const __UINT16_TYPE__ = c_ushort;
pub const __UINT16_FMTo__ = "ho";
pub const __UINT16_FMTu__ = "hu";
pub const __UINT16_FMTx__ = "hx";
pub const __UINT16_FMTX__ = "hX";
pub const __UINT16_C_SUFFIX__ = "";
pub const __UINT16_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_int, 65535, .decimal);
pub const __INT16_MAX__ = @as(c_int, 32767);
pub const __UINT32_TYPE__ = c_uint;
pub const __UINT32_FMTo__ = "o";
pub const __UINT32_FMTu__ = "u";
pub const __UINT32_FMTx__ = "x";
pub const __UINT32_FMTX__ = "X";
pub const __UINT32_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_uint, 4294967295, .decimal);
pub const __INT32_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_int, 2147483647, .decimal);
pub const __UINT64_TYPE__ = c_ulong;
pub const __UINT64_FMTo__ = "lo";
pub const __UINT64_FMTu__ = "lu";
pub const __UINT64_FMTx__ = "lx";
pub const __UINT64_FMTX__ = "lX";
pub const __UINT64_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_ulong, 18446744073709551615, .decimal);
pub const __INT64_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_long, 9223372036854775807, .decimal);
pub const __INT_LEAST8_TYPE__ = i8;
pub const __INT_LEAST8_MAX__ = @as(c_int, 127);
pub const __INT_LEAST8_FMTd__ = "hhd";
pub const __INT_LEAST8_FMTi__ = "hhi";
pub const __UINT_LEAST8_TYPE__ = u8;
pub const __UINT_LEAST8_MAX__ = @as(c_int, 255);
pub const __UINT_LEAST8_FMTo__ = "hho";
pub const __UINT_LEAST8_FMTu__ = "hhu";
pub const __UINT_LEAST8_FMTx__ = "hhx";
pub const __UINT_LEAST8_FMTX__ = "hhX";
pub const __INT_LEAST16_TYPE__ = c_short;
pub const __INT_LEAST16_MAX__ = @as(c_int, 32767);
pub const __INT_LEAST16_FMTd__ = "hd";
pub const __INT_LEAST16_FMTi__ = "hi";
pub const __UINT_LEAST16_TYPE__ = c_ushort;
pub const __UINT_LEAST16_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_int, 65535, .decimal);
pub const __UINT_LEAST16_FMTo__ = "ho";
pub const __UINT_LEAST16_FMTu__ = "hu";
pub const __UINT_LEAST16_FMTx__ = "hx";
pub const __UINT_LEAST16_FMTX__ = "hX";
pub const __INT_LEAST32_TYPE__ = c_int;
pub const __INT_LEAST32_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_int, 2147483647, .decimal);
pub const __INT_LEAST32_FMTd__ = "d";
pub const __INT_LEAST32_FMTi__ = "i";
pub const __UINT_LEAST32_TYPE__ = c_uint;
pub const __UINT_LEAST32_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_uint, 4294967295, .decimal);
pub const __UINT_LEAST32_FMTo__ = "o";
pub const __UINT_LEAST32_FMTu__ = "u";
pub const __UINT_LEAST32_FMTx__ = "x";
pub const __UINT_LEAST32_FMTX__ = "X";
pub const __INT_LEAST64_TYPE__ = c_long;
pub const __INT_LEAST64_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_long, 9223372036854775807, .decimal);
pub const __INT_LEAST64_FMTd__ = "ld";
pub const __INT_LEAST64_FMTi__ = "li";
pub const __UINT_LEAST64_TYPE__ = c_ulong;
pub const __UINT_LEAST64_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_ulong, 18446744073709551615, .decimal);
pub const __UINT_LEAST64_FMTo__ = "lo";
pub const __UINT_LEAST64_FMTu__ = "lu";
pub const __UINT_LEAST64_FMTx__ = "lx";
pub const __UINT_LEAST64_FMTX__ = "lX";
pub const __INT_FAST8_TYPE__ = i8;
pub const __INT_FAST8_MAX__ = @as(c_int, 127);
pub const __INT_FAST8_FMTd__ = "hhd";
pub const __INT_FAST8_FMTi__ = "hhi";
pub const __UINT_FAST8_TYPE__ = u8;
pub const __UINT_FAST8_MAX__ = @as(c_int, 255);
pub const __UINT_FAST8_FMTo__ = "hho";
pub const __UINT_FAST8_FMTu__ = "hhu";
pub const __UINT_FAST8_FMTx__ = "hhx";
pub const __UINT_FAST8_FMTX__ = "hhX";
pub const __INT_FAST16_TYPE__ = c_short;
pub const __INT_FAST16_MAX__ = @as(c_int, 32767);
pub const __INT_FAST16_FMTd__ = "hd";
pub const __INT_FAST16_FMTi__ = "hi";
pub const __UINT_FAST16_TYPE__ = c_ushort;
pub const __UINT_FAST16_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_int, 65535, .decimal);
pub const __UINT_FAST16_FMTo__ = "ho";
pub const __UINT_FAST16_FMTu__ = "hu";
pub const __UINT_FAST16_FMTx__ = "hx";
pub const __UINT_FAST16_FMTX__ = "hX";
pub const __INT_FAST32_TYPE__ = c_int;
pub const __INT_FAST32_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_int, 2147483647, .decimal);
pub const __INT_FAST32_FMTd__ = "d";
pub const __INT_FAST32_FMTi__ = "i";
pub const __UINT_FAST32_TYPE__ = c_uint;
pub const __UINT_FAST32_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_uint, 4294967295, .decimal);
pub const __UINT_FAST32_FMTo__ = "o";
pub const __UINT_FAST32_FMTu__ = "u";
pub const __UINT_FAST32_FMTx__ = "x";
pub const __UINT_FAST32_FMTX__ = "X";
pub const __INT_FAST64_TYPE__ = c_long;
pub const __INT_FAST64_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_long, 9223372036854775807, .decimal);
pub const __INT_FAST64_FMTd__ = "ld";
pub const __INT_FAST64_FMTi__ = "li";
pub const __UINT_FAST64_TYPE__ = c_ulong;
pub const __UINT_FAST64_MAX__ = @import("std").zig.c_translation.promoteIntLiteral(c_ulong, 18446744073709551615, .decimal);
pub const __UINT_FAST64_FMTo__ = "lo";
pub const __UINT_FAST64_FMTu__ = "lu";
pub const __UINT_FAST64_FMTx__ = "lx";
pub const __UINT_FAST64_FMTX__ = "lX";
pub const __USER_LABEL_PREFIX__ = "";
pub const __FINITE_MATH_ONLY__ = @as(c_int, 0);
pub const __GNUC_STDC_INLINE__ = @as(c_int, 1);
pub const __GCC_ATOMIC_TEST_AND_SET_TRUEVAL = @as(c_int, 1);
pub const __CLANG_ATOMIC_BOOL_LOCK_FREE = @as(c_int, 2);
pub const __CLANG_ATOMIC_CHAR_LOCK_FREE = @as(c_int, 2);
pub const __CLANG_ATOMIC_CHAR16_T_LOCK_FREE = @as(c_int, 2);
pub const __CLANG_ATOMIC_CHAR32_T_LOCK_FREE = @as(c_int, 2);
pub const __CLANG_ATOMIC_WCHAR_T_LOCK_FREE = @as(c_int, 2);
pub const __CLANG_ATOMIC_SHORT_LOCK_FREE = @as(c_int, 2);
pub const __CLANG_ATOMIC_INT_LOCK_FREE = @as(c_int, 2);
pub const __CLANG_ATOMIC_LONG_LOCK_FREE = @as(c_int, 2);
pub const __CLANG_ATOMIC_LLONG_LOCK_FREE = @as(c_int, 2);
pub const __CLANG_ATOMIC_POINTER_LOCK_FREE = @as(c_int, 2);
pub const __GCC_ATOMIC_BOOL_LOCK_FREE = @as(c_int, 2);
pub const __GCC_ATOMIC_CHAR_LOCK_FREE = @as(c_int, 2);
pub const __GCC_ATOMIC_CHAR16_T_LOCK_FREE = @as(c_int, 2);
pub const __GCC_ATOMIC_CHAR32_T_LOCK_FREE = @as(c_int, 2);
pub const __GCC_ATOMIC_WCHAR_T_LOCK_FREE = @as(c_int, 2);
pub const __GCC_ATOMIC_SHORT_LOCK_FREE = @as(c_int, 2);
pub const __GCC_ATOMIC_INT_LOCK_FREE = @as(c_int, 2);
pub const __GCC_ATOMIC_LONG_LOCK_FREE = @as(c_int, 2);
pub const __GCC_ATOMIC_LLONG_LOCK_FREE = @as(c_int, 2);
pub const __GCC_ATOMIC_POINTER_LOCK_FREE = @as(c_int, 2);
pub const __NO_INLINE__ = @as(c_int, 1);
pub const __FLT_EVAL_METHOD__ = @as(c_int, 0);
pub const __FLT_RADIX__ = @as(c_int, 2);
pub const __DECIMAL_DIG__ = __LDBL_DECIMAL_DIG__;
pub const __GCC_ASM_FLAG_OUTPUTS__ = @as(c_int, 1);
pub const __code_model_small__ = @as(c_int, 1);
pub const __amd64__ = @as(c_int, 1);
pub const __amd64 = @as(c_int, 1);
pub const __x86_64 = @as(c_int, 1);
pub const __x86_64__ = @as(c_int, 1);
pub const __SEG_GS = @as(c_int, 1);
pub const __SEG_FS = @as(c_int, 1);
pub const __znver3 = @as(c_int, 1);
pub const __znver3__ = @as(c_int, 1);
pub const __tune_znver3__ = @as(c_int, 1);
pub const __REGISTER_PREFIX__ = "";
pub const __NO_MATH_INLINES = @as(c_int, 1);
pub const __AES__ = @as(c_int, 1);
pub const __VAES__ = @as(c_int, 1);
pub const __PCLMUL__ = @as(c_int, 1);
pub const __VPCLMULQDQ__ = @as(c_int, 1);
pub const __LAHF_SAHF__ = @as(c_int, 1);
pub const __LZCNT__ = @as(c_int, 1);
pub const __RDRND__ = @as(c_int, 1);
pub const __FSGSBASE__ = @as(c_int, 1);
pub const __BMI__ = @as(c_int, 1);
pub const __BMI2__ = @as(c_int, 1);
pub const __POPCNT__ = @as(c_int, 1);
pub const __PRFCHW__ = @as(c_int, 1);
pub const __RDSEED__ = @as(c_int, 1);
pub const __ADX__ = @as(c_int, 1);
pub const __MOVBE__ = @as(c_int, 1);
pub const __SSE4A__ = @as(c_int, 1);
pub const __FMA__ = @as(c_int, 1);
pub const __F16C__ = @as(c_int, 1);
pub const __SHA__ = @as(c_int, 1);
pub const __FXSR__ = @as(c_int, 1);
pub const __XSAVE__ = @as(c_int, 1);
pub const __XSAVEOPT__ = @as(c_int, 1);
pub const __XSAVEC__ = @as(c_int, 1);
pub const __XSAVES__ = @as(c_int, 1);
pub const __CLFLUSHOPT__ = @as(c_int, 1);
pub const __CLWB__ = @as(c_int, 1);
pub const __CLZERO__ = @as(c_int, 1);
pub const __RDPID__ = @as(c_int, 1);
pub const __AVX2__ = @as(c_int, 1);
pub const __AVX__ = @as(c_int, 1);
pub const __SSE4_2__ = @as(c_int, 1);
pub const __SSE4_1__ = @as(c_int, 1);
pub const __SSSE3__ = @as(c_int, 1);
pub const __SSE3__ = @as(c_int, 1);
pub const __SSE2__ = @as(c_int, 1);
pub const __SSE2_MATH__ = @as(c_int, 1);
pub const __SSE__ = @as(c_int, 1);
pub const __SSE_MATH__ = @as(c_int, 1);
pub const __MMX__ = @as(c_int, 1);
pub const __GCC_HAVE_SYNC_COMPARE_AND_SWAP_1 = @as(c_int, 1);
pub const __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 = @as(c_int, 1);
pub const __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 = @as(c_int, 1);
pub const __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 = @as(c_int, 1);
pub const __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 = @as(c_int, 1);
pub const __SIZEOF_FLOAT128__ = @as(c_int, 16);
pub const unix = @as(c_int, 1);
pub const __unix = @as(c_int, 1);
pub const __unix__ = @as(c_int, 1);
pub const linux = @as(c_int, 1);
pub const __linux = @as(c_int, 1);
pub const __linux__ = @as(c_int, 1);
pub const __ELF__ = @as(c_int, 1);
pub const __gnu_linux__ = @as(c_int, 1);
pub const __FLOAT128__ = @as(c_int, 1);
pub const __STDC__ = @as(c_int, 1);
pub const __STDC_HOSTED__ = @as(c_int, 1);
pub const __STDC_VERSION__ = @as(c_long, 201710);
pub const __STDC_UTF_16__ = @as(c_int, 1);
pub const __STDC_UTF_32__ = @as(c_int, 1);
pub const _DEBUG = @as(c_int, 1);
pub const __GCC_HAVE_DWARF2_CFI_ASM = @as(c_int, 1);
pub const st_bigint = struct_st_bigint;

flexible_array.zig

// https://github.com/ziglang/zig/blob/0e26c61499c5116ca11d1bfedc691b56b23a0751/lib/std/zig/c_translation.zig#L346-L364
/// Constructs a [*c] pointer with the const and volatile annotations
/// from SelfType for pointing to a C flexible array of ElementType.
pub fn FlexibleArrayType(comptime SelfType: type, ElementType: type) type {
    switch (@typeInfo(SelfType)) {
        .Pointer => |ptr| {
            return @Type(.{ .Pointer = .{
                .size = .C,
                .is_const = ptr.is_const,
                .is_volatile = ptr.is_volatile,
                .alignment = @alignOf(ElementType),
                .address_space = .generic,
                .child = ElementType,
                .is_allowzero = true,
                .sentinel = null,
            } });
        },
        else => |info| @compileError("Invalid self type \"" ++ @tagName(info) ++ "\" for flexible array getter: " ++ @typeName(SelfType)),
    }
}