fmt/include/fmt/fmt-c.h
2026-03-13 17:51:48 -07:00

193 lines
6.4 KiB
C

// Formatting library for C++ - the C API
//
// Copyright (c) 2012 - present, Victor Zverovich
// All rights reserved.
//
// For the license information refer to format.h.
#ifndef FMT_C_H_
#define FMT_C_H_
#include <stdbool.h> // bool
#include <stddef.h> // size_t
#ifdef __cplusplus
extern "C" {
#endif
typedef enum {
fmt_int = 1,
fmt_uint,
fmt_bool = 7,
fmt_char,
fmt_float,
fmt_double,
fmt_long_double,
fmt_cstring,
fmt_pointer = 14
} fmt_type;
typedef struct {
fmt_type type;
union {
long long int_value;
unsigned long long uint_value; // Used for FMT_PTR and custom data
bool bool_value;
char char_value;
float float_value;
double double_value;
long double long_double_value;
const char* cstring;
const void* pointer;
} value;
} fmt_arg;
enum { fmt_error = -1, fmt_error_invalid_arg = -2 };
int fmt_vformat(char* buffer, size_t size, const char* fmt, const fmt_arg* args,
size_t num_args);
#ifdef __cplusplus
}
#endif
#ifndef __cplusplus
static inline fmt_arg fmt_from_int(long long x) {
return (fmt_arg){.type = fmt_int, .value.int_value = x};
}
static inline fmt_arg fmt_from_uint(unsigned long long x) {
return (fmt_arg){.type = fmt_uint, .value.uint_value = x};
}
static inline fmt_arg fmt_from_bool(bool x) {
return (fmt_arg){.type = fmt_bool, .value.bool_value = x};
}
static inline fmt_arg fmt_from_char(char x) {
return (fmt_arg){.type = fmt_char, .value.char_value = x};
}
static inline fmt_arg fmt_from_float(float x) {
return (fmt_arg){.type = fmt_float, .value.float_value = x};
}
static inline fmt_arg fmt_from_double(double x) {
return (fmt_arg){.type = fmt_double, .value.double_value = x};
}
static inline fmt_arg fmt_from_long_double(long double x) {
return (fmt_arg){.type = fmt_long_double, .value.long_double_value = x};
}
static inline fmt_arg fmt_from_str(const char* x) {
return (fmt_arg){.type = fmt_cstring, .value.cstring = x};
}
static inline fmt_arg fmt_from_ptr(const void* x) {
return (fmt_arg){.type = fmt_pointer, .value.pointer = x};
}
void fmt_unsupported_type(void);
# if !defined(_MSC_VER) || defined(__clang__)
typedef signed char fmt_signed_char;
# else
typedef enum {} fmt_signed_char;
# endif
// Require modern MSVC with conformant preprocessor.
# if defined(_MSC_VER) && !defined(__clang__) && \
(!defined(_MSVC_TRADITIONAL) || _MSVC_TRADITIONAL)
# error "C API requires MSVC 2019+ with /Zc:preprocessor flag."
# endif
# define FMT_MAKE_ARG(x) \
_Generic((x), \
fmt_signed_char: fmt_from_int, \
unsigned char: fmt_from_uint, \
short: fmt_from_int, \
unsigned short: fmt_from_uint, \
int: fmt_from_int, \
unsigned int: fmt_from_uint, \
long: fmt_from_int, \
unsigned long: fmt_from_uint, \
long long: fmt_from_int, \
unsigned long long: fmt_from_uint, \
bool: fmt_from_bool, \
char: fmt_from_char, \
float: fmt_from_float, \
double: fmt_from_double, \
long double: fmt_from_long_double, \
char*: fmt_from_str, \
const char*: fmt_from_str, \
void*: fmt_from_ptr, \
const void*: fmt_from_ptr, \
default: fmt_unsupported_type)(x)
# define FMT_CAT(a, b) FMT_CAT_(a, b)
# define FMT_CAT_(a, b) a##b
# define FMT_NARG_(_unused, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, \
_12, _13, _14, _15, _16, N, ...) \
N
# define FMT_NARG(_unused, ...) \
FMT_NARG_(, ##__VA_ARGS__, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, \
3, 2, 1, 0)
# define FMT_MAP_0(...)
# define FMT_MAP_1(f, a) f(a)
# define FMT_MAP_2(f, a, b) f(a), f(b)
# define FMT_MAP_3(f, a, b, c) f(a), f(b), f(c)
# define FMT_MAP_4(f, a, b, c, d) f(a), f(b), f(c), f(d)
# define FMT_MAP_5(f, a, b, c, d, e) f(a), f(b), f(c), f(d), f(e)
# define FMT_MAP_6(f, a, b, c, d, e, g) f(a), f(b), f(c), f(d), f(e), f(g)
# define FMT_MAP_7(f, a, b, c, d, e, g, h) \
f(a), f(b), f(c), f(d), f(e), f(g), f(h)
# define FMT_MAP_8(f, a, b, c, d, e, g, h, i) \
f(a), f(b), f(c), f(d), f(e), f(g), f(h), f(i)
# define FMT_MAP_9(f, a, b, c, d, e, g, h, i, j) \
f(a), f(b), f(c), f(d), f(e), f(g), f(h), f(i), f(j)
# define FMT_MAP_10(f, a, b, c, d, e, g, h, i, j, k) \
f(a), f(b), f(c), f(d), f(e), f(g), f(h), f(i), f(j), f(k)
# define FMT_MAP_11(f, a, b, c, d, e, g, h, i, j, k, l) \
f(a), f(b), f(c), f(d), f(e), f(g), f(h), f(i), f(j), f(k), f(l)
# define FMT_MAP_12(f, a, b, c, d, e, g, h, i, j, k, l, m) \
f(a), f(b), f(c), f(d), f(e), f(g), f(h), f(i), f(j), f(k), f(l), f(m)
# define FMT_MAP_13(f, a, b, c, d, e, g, h, i, j, k, l, m, n) \
f(a), f(b), f(c), f(d), f(e), f(g), f(h), f(i), f(j), f(k), f(l), f(m), f(n)
# define FMT_MAP_14(f, a, b, c, d, e, g, h, i, j, k, l, m, n, o) \
f(a), f(b), f(c), f(d), f(e), f(g), f(h), f(i), f(j), f(k), f(l), f(m), \
f(n), f(o)
# define FMT_MAP_15(f, a, b, c, d, e, g, h, i, j, k, l, m, n, o, p) \
f(a), f(b), f(c), f(d), f(e), f(g), f(h), f(i), f(j), f(k), f(l), f(m), \
f(n), f(o), f(p)
# define FMT_MAP_16(f, a, b, c, d, e, g, h, i, j, k, l, m, n, o, p, q) \
f(a), f(b), f(c), f(d), f(e), f(g), f(h), f(i), f(j), f(k), f(l), f(m), \
f(n), f(o), f(p), f(q)
# define FMT_MAP(f, ...) \
FMT_CAT(FMT_MAP_, FMT_NARG(, ##__VA_ARGS__))(f, ##__VA_ARGS__)
// select between two expressions depending on whether __VA_ARGS__ is empty
// expands to e if __VA_ARGS__ is empty and n otherwise
# define FMT_VA_SELECT(e, n, ...) \
FMT_NARG_(, ##__VA_ARGS__, n, n, n, n, n, n, n, n, n, n, n, n, n, n, n, n, \
e)
# define FMT_MAKE_NULL(...) NULL
# define FMT_MAKE_ARGLIST(...) \
(fmt_arg[]) { FMT_MAP(FMT_MAKE_ARG, ##__VA_ARGS__) }
# define FMT_EXPAND(v) v
# define fmt_format(buffer, size, fmt, ...) \
fmt_vformat((buffer), (size), (fmt), \
FMT_EXPAND(FMT_VA_SELECT(FMT_MAKE_NULL, FMT_MAKE_ARGLIST, \
##__VA_ARGS__)(__VA_ARGS__)), \
FMT_NARG(, ##__VA_ARGS__))
#endif // __cplusplus
#endif // FMT_C_H_