Alignment and fill options only apply to numbers.
Rework the implementation to mainly branch on the format string rather
than the type information. This is more straightforward to maintain and
more straightforward for comptime evaluation.
Enums support being printed as decimal, hexadecimal, octal, and binary.
`formatInteger` is another possible format method that is
unconditionally called when the value type is struct and one of the
integer-printing format specifiers are used.
for structs, enums, and unions.
auto untagged unions are no longer printed as pointers; instead they are
printed as "{ ... }".
extern and packed untagged unions have each field printed, similar to
what gdb does.
also fix bugs in delimiter based reading
added adapter to AnyWriter and GenericWriter to help bridge the gap
between old and new API
make std.testing.expectFmt work at compile-time
std.fmt no longer has a dependency on std.unicode. Formatted printing
was never properly unicode-aware. Now it no longer pretends to be.
Breakage/deprecations:
* std.fs.File.reader -> std.fs.File.deprecatedReader
* std.fs.File.writer -> std.fs.File.deprecatedWriter
* std.io.GenericReader -> std.io.Reader
* std.io.GenericWriter -> std.io.Writer
* std.io.AnyReader -> std.io.Reader
* std.io.AnyWriter -> std.io.Writer
* std.fmt.format -> std.fmt.deprecatedFormat
* std.fmt.fmtSliceEscapeLower -> std.ascii.hexEscape
* std.fmt.fmtSliceEscapeUpper -> std.ascii.hexEscape
* std.fmt.fmtSliceHexLower -> {x}
* std.fmt.fmtSliceHexUpper -> {X}
* std.fmt.fmtIntSizeDec -> {B}
* std.fmt.fmtIntSizeBin -> {Bi}
* std.fmt.fmtDuration -> {D}
* std.fmt.fmtDurationSigned -> {D}
* {} -> {f} when there is a format method
* format method signature
- anytype -> *std.io.Writer
- inferred error set -> error{WriteFailed}
- options -> (deleted)
* std.fmt.Formatted
- now takes context type explicitly
- no fmt string
into the vtable
also break `drainTo` and `sendFileTo` into lower level primitives
`writeSplatHeader` and `sendFileHeader` respectively. these are easier
to reason about in drain implementations.
