Source
pub fn formatInt(
value: anytype,
base: u8,
case: Case,
options: FormatOptions,
writer: anytype,
) !void {
assert(base >= 2);
const int_value = if (@TypeOf(value) == comptime_int) blk: {
const Int = math.IntFittingRange(value, value);
break :blk @as(Int, value);
} else value;
const value_info = @typeInfo(@TypeOf(int_value)).int;
// The type must have the same size as `base` or be wider in order for the
// division to work
const min_int_bits = comptime @max(value_info.bits, 8);
const MinInt = std.meta.Int(.unsigned, min_int_bits);
const abs_value = @abs(int_value);
// The worst case in terms of space needed is base 2, plus 1 for the sign
var buf: [1 + @max(@as(comptime_int, value_info.bits), 1)]u8 = undefined;
var a: MinInt = abs_value;
var index: usize = buf.len;
if (base == 10) {
while (a >= 100) : (a = @divTrunc(a, 100)) {
index -= 2;
buf[index..][0..2].* = digits2(@intCast(a % 100));
}
if (a < 10) {
index -= 1;
buf[index] = '0' + @as(u8, @intCast(a));
} else {
index -= 2;
buf[index..][0..2].* = digits2(@intCast(a));
}
} else {
while (true) {
const digit = a % base;
index -= 1;
buf[index] = digitToChar(@intCast(digit), case);
a /= base;
if (a == 0) break;
}
}
if (value_info.signedness == .signed) {
if (value < 0) {
// Negative integer
index -= 1;
buf[index] = '-';
} else if (options.width == null or options.width.? == 0) {
// Positive integer, omit the plus sign
} else {
// Positive integer
index -= 1;
buf[index] = '+';
}
}
return formatBuf(buf[index..], options, writer);
}