done but dirty

This commit is contained in:
Glen Stark 2016-05-27 17:50:25 +02:00
parent 321a541ee9
commit 0cf85df251
4 changed files with 453 additions and 410 deletions

View File

@ -25,13 +25,13 @@
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/ */
#include "fmt/printf_formatter.h"
#include "fmt/format.h" #include "fmt/format.h"
#include <string.h> #include <string.h>
#include <cctype> #include <cctype>
#include <cerrno> #include <cerrno>
#include <climits>
#include <cmath> #include <cmath>
#include <cstdarg> #include <cstdarg>
#include <cstddef> // for std::ptrdiff_t #include <cstddef> // for std::ptrdiff_t
@ -81,45 +81,6 @@ static inline fmt::internal::Null<> strerror_s(char *, std::size_t, ...) {
namespace fmt { namespace fmt {
namespace { namespace {
#ifndef _MSC_VER
# define FMT_SNPRINTF snprintf
#else // _MSC_VER
inline int fmt_snprintf(char *buffer, size_t size, const char *format, ...) {
va_list args;
va_start(args, format);
int result = vsnprintf_s(buffer, size, _TRUNCATE, format, args);
va_end(args);
return result;
}
# define FMT_SNPRINTF fmt_snprintf
#endif // _MSC_VER
#if defined(_WIN32) && defined(__MINGW32__) && !defined(__NO_ISOCEXT)
# define FMT_SWPRINTF snwprintf
#else
# define FMT_SWPRINTF swprintf
#endif // defined(_WIN32) && defined(__MINGW32__) && !defined(__NO_ISOCEXT)
// Checks if a value fits in int - used to avoid warnings about comparing
// signed and unsigned integers.
template <bool IsSigned>
struct IntChecker {
template <typename T>
static bool fits_in_int(T value) {
unsigned max = INT_MAX;
return value <= max;
}
static bool fits_in_int(bool) { return true; }
};
template <>
struct IntChecker<true> {
template <typename T>
static bool fits_in_int(T value) {
return value >= INT_MIN && value <= INT_MAX;
}
static bool fits_in_int(int) { return true; }
};
const char RESET_COLOR[] = "\x1b[0m"; const char RESET_COLOR[] = "\x1b[0m";
@ -226,135 +187,6 @@ void report_error(FormatFunc func, int error_code,
std::fputc('\n', stderr); std::fputc('\n', stderr);
} }
// IsZeroInt::visit(arg) returns true iff arg is a zero integer.
class IsZeroInt : public ArgVisitor<IsZeroInt, bool> {
public:
template <typename T>
bool visit_any_int(T value) { return value == 0; }
};
// Checks if an argument is a valid printf width specifier and sets
// left alignment if it is negative.
class WidthHandler : public ArgVisitor<WidthHandler, unsigned> {
private:
FormatSpec &spec_;
FMT_DISALLOW_COPY_AND_ASSIGN(WidthHandler);
public:
explicit WidthHandler(FormatSpec &spec) : spec_(spec) {}
void report_unhandled_arg() {
FMT_THROW(FormatError("width is not integer"));
}
template <typename T>
unsigned visit_any_int(T value) {
typedef typename internal::IntTraits<T>::MainType UnsignedType;
UnsignedType width = static_cast<UnsignedType>(value);
if (internal::is_negative(value)) {
spec_.align_ = ALIGN_LEFT;
width = 0 - width;
}
if (width > INT_MAX)
FMT_THROW(FormatError("number is too big"));
return static_cast<unsigned>(width);
}
};
class PrecisionHandler : public ArgVisitor<PrecisionHandler, int> {
public:
void report_unhandled_arg() {
FMT_THROW(FormatError("precision is not integer"));
}
template <typename T>
int visit_any_int(T value) {
if (!IntChecker<std::numeric_limits<T>::is_signed>::fits_in_int(value))
FMT_THROW(FormatError("number is too big"));
return static_cast<int>(value);
}
};
template <typename T, typename U>
struct is_same {
enum { value = 0 };
};
template <typename T>
struct is_same<T, T> {
enum { value = 1 };
};
// An argument visitor that converts an integer argument to T for printf,
// if T is an integral type. If T is void, the argument is converted to
// corresponding signed or unsigned type depending on the type specifier:
// 'd' and 'i' - signed, other - unsigned)
template <typename T = void>
class ArgConverter : public ArgVisitor<ArgConverter<T>, void> {
private:
internal::Arg &arg_;
wchar_t type_;
FMT_DISALLOW_COPY_AND_ASSIGN(ArgConverter);
public:
ArgConverter(internal::Arg &arg, wchar_t type)
: arg_(arg), type_(type) {}
void visit_bool(bool value) {
if (type_ != 's')
visit_any_int(value);
}
template <typename U>
void visit_any_int(U value) {
bool is_signed = type_ == 'd' || type_ == 'i';
using internal::Arg;
typedef typename internal::Conditional<
is_same<T, void>::value, U, T>::type TargetType;
if (sizeof(TargetType) <= sizeof(int)) {
// Extra casts are used to silence warnings.
if (is_signed) {
arg_.type = Arg::INT;
arg_.int_value = static_cast<int>(static_cast<TargetType>(value));
} else {
arg_.type = Arg::UINT;
typedef typename internal::MakeUnsigned<TargetType>::Type Unsigned;
arg_.uint_value = static_cast<unsigned>(static_cast<Unsigned>(value));
}
} else {
if (is_signed) {
arg_.type = Arg::LONG_LONG;
// glibc's printf doesn't sign extend arguments of smaller types:
// std::printf("%lld", -42); // prints "4294967254"
// but we don't have to do the same because it's a UB.
arg_.long_long_value = static_cast<LongLong>(value);
} else {
arg_.type = Arg::ULONG_LONG;
arg_.ulong_long_value =
static_cast<typename internal::MakeUnsigned<U>::Type>(value);
}
}
}
};
// Converts an integer argument to char for printf.
class CharConverter : public ArgVisitor<CharConverter, void> {
private:
internal::Arg &arg_;
FMT_DISALLOW_COPY_AND_ASSIGN(CharConverter);
public:
explicit CharConverter(internal::Arg &arg) : arg_(arg) {}
template <typename T>
void visit_any_int(T value) {
arg_.type = internal::Arg::CHAR;
arg_.int_value = static_cast<char>(value);
}
};
} // namespace } // namespace
namespace internal { namespace internal {
@ -366,74 +198,6 @@ FMT_FUNC void format_system_error(
fmt::format_system_error(out, error_code, message); fmt::format_system_error(out, error_code, message);
} }
template <typename Char>
class PrintfArgFormatter :
public ArgFormatterBase<PrintfArgFormatter<Char>, Char> {
void write_null_pointer() {
this->spec().type_ = 0;
this->write("(nil)");
}
typedef ArgFormatterBase<PrintfArgFormatter<Char>, Char> Base;
public:
PrintfArgFormatter(BasicWriter<Char> &w, FormatSpec &s)
: ArgFormatterBase<PrintfArgFormatter<Char>, Char>(w, s) {}
void visit_bool(bool value) {
FormatSpec &fmt_spec = this->spec();
if (fmt_spec.type_ != 's')
return this->visit_any_int(value);
fmt_spec.type_ = 0;
this->write(value);
}
void visit_char(int value) {
const FormatSpec &fmt_spec = this->spec();
BasicWriter<Char> &w = this->writer();
if (fmt_spec.type_ && fmt_spec.type_ != 'c')
w.write_int(value, fmt_spec);
typedef typename BasicWriter<Char>::CharPtr CharPtr;
CharPtr out = CharPtr();
if (fmt_spec.width_ > 1) {
Char fill = ' ';
out = w.grow_buffer(fmt_spec.width_);
if (fmt_spec.align_ != ALIGN_LEFT) {
std::fill_n(out, fmt_spec.width_ - 1, fill);
out += fmt_spec.width_ - 1;
} else {
std::fill_n(out + 1, fmt_spec.width_ - 1, fill);
}
} else {
out = w.grow_buffer(1);
}
*out = static_cast<Char>(value);
}
void visit_cstring(const char *value) {
if (value)
Base::visit_cstring(value);
else if (this->spec().type_ == 'p')
write_null_pointer();
else
this->write("(null)");
}
void visit_pointer(const void *value) {
if (value)
return Base::visit_pointer(value);
this->spec().type_ = 0;
write_null_pointer();
}
void visit_custom(Arg::CustomValue c) {
BasicFormatter<Char> formatter(ArgList(), this->writer());
const Char format_str[] = {'}', 0};
const Char *format = format_str;
c.format(&formatter, c.value, &format);
}
};
} // namespace internal } // namespace internal
} // namespace fmt } // namespace fmt
@ -686,177 +450,6 @@ FMT_FUNC Arg fmt::internal::FormatterBase::do_get_arg(
return arg; return arg;
} }
template <typename Char, typename PAF>
void fmt::internal::PrintfFormatter<Char, PAF>::parse_flags(
FormatSpec &spec, const Char *&s) {
for (;;) {
switch (*s++) {
case '-':
spec.align_ = ALIGN_LEFT;
break;
case '+':
spec.flags_ |= SIGN_FLAG | PLUS_FLAG;
break;
case '0':
spec.fill_ = '0';
break;
case ' ':
spec.flags_ |= SIGN_FLAG;
break;
case '#':
spec.flags_ |= HASH_FLAG;
break;
default:
--s;
return;
}
}
}
template <typename Char, typename PAF>
Arg fmt::internal::PrintfFormatter<Char, PAF>::get_arg(
const Char *s, unsigned arg_index) {
(void)s;
const char *error = 0;
Arg arg = arg_index == UINT_MAX ?
next_arg(error) : FormatterBase::get_arg(arg_index - 1, error);
if (error)
FMT_THROW(FormatError(!*s ? "invalid format string" : error));
return arg;
}
template <typename Char, typename PAF>
unsigned fmt::internal::PrintfFormatter<Char, PAF>::parse_header(
const Char *&s, FormatSpec &spec) {
unsigned arg_index = UINT_MAX;
Char c = *s;
if (c >= '0' && c <= '9') {
// Parse an argument index (if followed by '$') or a width possibly
// preceded with '0' flag(s).
unsigned value = parse_nonnegative_int(s);
if (*s == '$') { // value is an argument index
++s;
arg_index = value;
} else {
if (c == '0')
spec.fill_ = '0';
if (value != 0) {
// Nonzero value means that we parsed width and don't need to
// parse it or flags again, so return now.
spec.width_ = value;
return arg_index;
}
}
}
parse_flags(spec, s);
// Parse width.
if (*s >= '0' && *s <= '9') {
spec.width_ = parse_nonnegative_int(s);
} else if (*s == '*') {
++s;
spec.width_ = WidthHandler(spec).visit(get_arg(s));
}
return arg_index;
}
template <typename Char, typename PAF >
void fmt::internal::PrintfFormatter<Char,PAF>::format(
BasicWriter<Char> &writer, BasicCStringRef<Char> format_str) {
const Char *start = format_str.c_str();
const Char *s = start;
while (*s) {
Char c = *s++;
if (c != '%') continue;
if (*s == c) {
write(writer, start, s);
start = ++s;
continue;
}
write(writer, start, s - 1);
FormatSpec spec;
spec.align_ = ALIGN_RIGHT;
// Parse argument index, flags and width.
unsigned arg_index = parse_header(s, spec);
// Parse precision.
if (*s == '.') {
++s;
if ('0' <= *s && *s <= '9') {
spec.precision_ = static_cast<int>(parse_nonnegative_int(s));
} else if (*s == '*') {
++s;
spec.precision_ = PrecisionHandler().visit(get_arg(s));
}
}
Arg arg = get_arg(s, arg_index);
if (spec.flag(HASH_FLAG) && IsZeroInt().visit(arg))
spec.flags_ &= ~to_unsigned<int>(HASH_FLAG);
if (spec.fill_ == '0') {
if (arg.type <= Arg::LAST_NUMERIC_TYPE)
spec.align_ = ALIGN_NUMERIC;
else
spec.fill_ = ' '; // Ignore '0' flag for non-numeric types.
}
// Parse length and convert the argument to the required type.
switch (*s++) {
case 'h':
if (*s == 'h')
ArgConverter<signed char>(arg, *++s).visit(arg);
else
ArgConverter<short>(arg, *s).visit(arg);
break;
case 'l':
if (*s == 'l')
ArgConverter<fmt::LongLong>(arg, *++s).visit(arg);
else
ArgConverter<long>(arg, *s).visit(arg);
break;
case 'j':
ArgConverter<intmax_t>(arg, *s).visit(arg);
break;
case 'z':
ArgConverter<std::size_t>(arg, *s).visit(arg);
break;
case 't':
ArgConverter<std::ptrdiff_t>(arg, *s).visit(arg);
break;
case 'L':
// printf produces garbage when 'L' is omitted for long double, no
// need to do the same.
break;
default:
--s;
ArgConverter<void>(arg, *s).visit(arg);
}
// Parse type.
if (!*s)
FMT_THROW(FormatError("invalid format string"));
spec.type_ = static_cast<char>(*s++);
if (arg.type <= Arg::LAST_INTEGER_TYPE) {
// Normalize type.
switch (spec.type_) {
case 'i': case 'u':
spec.type_ = 'd';
break;
case 'c':
// TODO: handle wchar_t
CharConverter(arg).visit(arg);
break;
}
}
start = s;
// Format argument.
PAF(writer, spec).visit(arg);
}
write(writer, start, s);
}
FMT_FUNC void fmt::report_system_error( FMT_FUNC void fmt::report_system_error(

431
fmt/printf_formatter.h Normal file
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@ -0,0 +1,431 @@
#ifndef H_PRINTF_FORMATTER
#define H_PRINTF_FORMATTER
#include "fmt/format.h"
#include <climits>
// Everyting that was in an anonymous namespace in format.cc goes in internal now:
namespace fmt {
namespace internal{
template <typename T, typename U>
struct is_same {
enum { value = 0 };
};
template <typename T>
struct is_same<T, T> {
enum { value = 1 };
};
}
// An argument visitor that converts an integer argument to T for printf,
// if T is an integral type. If T is void, the argument is converted to
// corresponding signed or unsigned type depending on the type specifier:
// 'd' and 'i' - signed, other - unsigned)
template <typename T = void>
class ArgConverter : public ArgVisitor<ArgConverter<T>, void> {
private:
internal::Arg &arg_;
wchar_t type_;
FMT_DISALLOW_COPY_AND_ASSIGN(ArgConverter);
public:
ArgConverter(internal::Arg &arg, wchar_t type)
: arg_(arg), type_(type) {}
void visit_bool(bool value) {
if (type_ != 's')
visit_any_int(value);
}
template <typename U>
void visit_any_int(U value) {
bool is_signed = type_ == 'd' || type_ == 'i';
using internal::Arg;
typedef typename internal::Conditional<internal::is_same<T, void>::value, U, T>::type TargetType;
if (sizeof(TargetType) <= sizeof(int)) {
// Extra casts are used to silence warnings.
if (is_signed) {
arg_.type = Arg::INT;
arg_.int_value = static_cast<int>(static_cast<TargetType>(value));
} else {
arg_.type = Arg::UINT;
typedef typename internal::MakeUnsigned<TargetType>::Type Unsigned;
arg_.uint_value = static_cast<unsigned>(static_cast<Unsigned>(value));
}
} else {
if (is_signed) {
arg_.type = Arg::LONG_LONG;
// glibc's printf doesn't sign extend arguments of smaller types:
// std::printf("%lld", -42); // prints "4294967254"
// but we don't have to do the same because it's a UB.
arg_.long_long_value = static_cast<LongLong>(value);
} else {
arg_.type = Arg::ULONG_LONG;
arg_.ulong_long_value =
static_cast<typename internal::MakeUnsigned<U>::Type>(value);
}
}
}
};
// Converts an integer argument to char for printf.
class CharConverter : public ArgVisitor<CharConverter, void> {
private:
internal::Arg &arg_;
FMT_DISALLOW_COPY_AND_ASSIGN(CharConverter);
public:
explicit CharConverter(internal::Arg &arg) : arg_(arg) {}
template <typename T>
void visit_any_int(T value) {
arg_.type = internal::Arg::CHAR;
arg_.int_value = static_cast<char>(value);
}
};
namespace internal {
#ifndef _MSC_VER
# define FMT_SNPRINTF snprintf
#else // _MSC_VER
inline int fmt_snprintf(char *buffer, size_t size, const char *format, ...) {
va_list args;
va_start(args, format);
int result = vsnprintf_s(buffer, size, _TRUNCATE, format, args);
va_end(args);
return result;
}
# define FMT_SNPRINTF fmt_snprintf
#endif // _MSC_VER
#if defined(_WIN32) && defined(__MINGW32__) && !defined(__NO_ISOCEXT)
# define FMT_SWPRINTF snwprintf
#else
# define FMT_SWPRINTF swprintf
#endif // defined(_WIN32) && defined(__MINGW32__) && !defined(__NO_ISOCEXT)
// Checks if a value fits in int - used to avoid warnings about comparing
// signed and unsigned integers.
template <bool IsSigned>
struct IntChecker {
template <typename T>
static bool fits_in_int(T value) {
unsigned max = INT_MAX;
return value <= max;
}
static bool fits_in_int(bool) { return true; }
};
template <>
struct IntChecker<true> {
template <typename T>
static bool fits_in_int(T value) {
return value >= INT_MIN && value <= INT_MAX;
}
static bool fits_in_int(int) { return true; }
};
class PrecisionHandler : public ArgVisitor<PrecisionHandler, int> {
public:
void report_unhandled_arg() {
FMT_THROW(FormatError("precision is not integer"));
}
template <typename T>
int visit_any_int(T value) {
if (!IntChecker<std::numeric_limits<T>::is_signed>::fits_in_int(value))
FMT_THROW(FormatError("number is too big"));
return static_cast<int>(value);
}
};
// IsZeroInt::visit(arg) returns true iff arg is a zero integer.
class IsZeroInt : public ArgVisitor<IsZeroInt, bool> {
public:
template <typename T>
bool visit_any_int(T value) { return value == 0; }
};
// Checks if an argument is a valid printf width specifier and sets
// left alignment if it is negative.
class WidthHandler : public ArgVisitor<WidthHandler, unsigned> {
private:
FormatSpec &spec_;
FMT_DISALLOW_COPY_AND_ASSIGN(WidthHandler);
public:
explicit WidthHandler(FormatSpec &spec) : spec_(spec) {}
void report_unhandled_arg() {
FMT_THROW(FormatError("width is not integer"));
}
template <typename T>
unsigned visit_any_int(T value) {
typedef typename internal::IntTraits<T>::MainType UnsignedType;
UnsignedType width = static_cast<UnsignedType>(value);
if (internal::is_negative(value)) {
spec_.align_ = ALIGN_LEFT;
width = 0 - width;
}
if (width > INT_MAX)
FMT_THROW(FormatError("number is too big"));
return static_cast<unsigned>(width);
}
};
template <typename Char>
class PrintfArgFormatter :
public ArgFormatterBase<PrintfArgFormatter<Char>, Char> {
void write_null_pointer() {
this->spec().type_ = 0;
this->write("(nil)");
}
typedef ArgFormatterBase<PrintfArgFormatter<Char>, Char> Base;
public:
PrintfArgFormatter(BasicWriter<Char> &w, FormatSpec &s)
: ArgFormatterBase<PrintfArgFormatter<Char>, Char>(w, s) {}
void visit_bool(bool value) {
FormatSpec &fmt_spec = this->spec();
if (fmt_spec.type_ != 's')
return this->visit_any_int(value);
fmt_spec.type_ = 0;
this->write(value);
}
void visit_char(int value) {
const FormatSpec &fmt_spec = this->spec();
BasicWriter<Char> &w = this->writer();
if (fmt_spec.type_ && fmt_spec.type_ != 'c')
w.write_int(value, fmt_spec);
typedef typename BasicWriter<Char>::CharPtr CharPtr;
CharPtr out = CharPtr();
if (fmt_spec.width_ > 1) {
Char fill = ' ';
out = w.grow_buffer(fmt_spec.width_);
if (fmt_spec.align_ != ALIGN_LEFT) {
std::fill_n(out, fmt_spec.width_ - 1, fill);
out += fmt_spec.width_ - 1;
} else {
std::fill_n(out + 1, fmt_spec.width_ - 1, fill);
}
} else {
out = w.grow_buffer(1);
}
*out = static_cast<Char>(value);
}
void visit_cstring(const char *value) {
if (value)
Base::visit_cstring(value);
else if (this->spec().type_ == 'p')
write_null_pointer();
else
this->write("(null)");
}
void visit_pointer(const void *value) {
if (value)
return Base::visit_pointer(value);
this->spec().type_ = 0;
write_null_pointer();
}
void visit_custom(Arg::CustomValue c) {
BasicFormatter<Char> formatter(ArgList(), this->writer());
const Char format_str[] = {'}', 0};
const Char *format = format_str;
c.format(&formatter, c.value, &format);
}
};
template <typename Char, typename PAF>
void fmt::internal::PrintfFormatter<Char, PAF>::parse_flags(
FormatSpec &spec, const Char *&s) {
for (;;) {
switch (*s++) {
case '-':
spec.align_ = ALIGN_LEFT;
break;
case '+':
spec.flags_ |= SIGN_FLAG | PLUS_FLAG;
break;
case '0':
spec.fill_ = '0';
break;
case ' ':
spec.flags_ |= SIGN_FLAG;
break;
case '#':
spec.flags_ |= HASH_FLAG;
break;
default:
--s;
return;
}
}
}
template <typename Char, typename PAF>
Arg fmt::internal::PrintfFormatter<Char, PAF>::get_arg(
const Char *s, unsigned arg_index) {
(void)s;
const char *error = 0;
Arg arg = arg_index == UINT_MAX ?
next_arg(error) : FormatterBase::get_arg(arg_index - 1, error);
if (error)
FMT_THROW(FormatError(!*s ? "invalid format string" : error));
return arg;
}
template <typename Char, typename PAF>
unsigned fmt::internal::PrintfFormatter<Char, PAF>::parse_header(
const Char *&s, FormatSpec &spec) {
unsigned arg_index = UINT_MAX;
Char c = *s;
if (c >= '0' && c <= '9') {
// Parse an argument index (if followed by '$') or a width possibly
// preceded with '0' flag(s).
unsigned value = parse_nonnegative_int(s);
if (*s == '$') { // value is an argument index
++s;
arg_index = value;
} else {
if (c == '0')
spec.fill_ = '0';
if (value != 0) {
// Nonzero value means that we parsed width and don't need to
// parse it or flags again, so return now.
spec.width_ = value;
return arg_index;
}
}
}
parse_flags(spec, s);
// Parse width.
if (*s >= '0' && *s <= '9') {
spec.width_ = parse_nonnegative_int(s);
} else if (*s == '*') {
++s;
spec.width_ = WidthHandler(spec).visit(get_arg(s));
}
return arg_index;
}
template <typename Char, typename PAF >
void fmt::internal::PrintfFormatter<Char,PAF>::format(
BasicWriter<Char> &writer, BasicCStringRef<Char> format_str) {
const Char *start = format_str.c_str();
const Char *s = start;
while (*s) {
Char c = *s++;
if (c != '%') continue;
if (*s == c) {
write(writer, start, s);
start = ++s;
continue;
}
write(writer, start, s - 1);
FormatSpec spec;
spec.align_ = ALIGN_RIGHT;
// Parse argument index, flags and width.
unsigned arg_index = parse_header(s, spec);
// Parse precision.
if (*s == '.') {
++s;
if ('0' <= *s && *s <= '9') {
spec.precision_ = static_cast<int>(parse_nonnegative_int(s));
} else if (*s == '*') {
++s;
spec.precision_ = PrecisionHandler().visit(get_arg(s));
}
}
Arg arg = get_arg(s, arg_index);
if (spec.flag(HASH_FLAG) && IsZeroInt().visit(arg))
spec.flags_ &= ~to_unsigned<int>(HASH_FLAG);
if (spec.fill_ == '0') {
if (arg.type <= Arg::LAST_NUMERIC_TYPE)
spec.align_ = ALIGN_NUMERIC;
else
spec.fill_ = ' '; // Ignore '0' flag for non-numeric types.
}
// Parse length and convert the argument to the required type.
switch (*s++) {
case 'h':
if (*s == 'h')
ArgConverter<signed char>(arg, *++s).visit(arg);
else
ArgConverter<short>(arg, *s).visit(arg);
break;
case 'l':
if (*s == 'l')
ArgConverter<fmt::LongLong>(arg, *++s).visit(arg);
else
ArgConverter<long>(arg, *s).visit(arg);
break;
case 'j':
ArgConverter<intmax_t>(arg, *s).visit(arg);
break;
case 'z':
ArgConverter<std::size_t>(arg, *s).visit(arg);
break;
case 't':
ArgConverter<std::ptrdiff_t>(arg, *s).visit(arg);
break;
case 'L':
// printf produces garbage when 'L' is omitted for long double, no
// need to do the same.
break;
default:
--s;
ArgConverter<void>(arg, *s).visit(arg);
}
// Parse type.
if (!*s)
FMT_THROW(FormatError("invalid format string"));
spec.type_ = static_cast<char>(*s++);
if (arg.type <= Arg::LAST_INTEGER_TYPE) {
// Normalize type.
switch (spec.type_) {
case 'i': case 'u':
spec.type_ = 'd';
break;
case 'c':
// TODO: handle wchar_t
CharConverter(arg).visit(arg);
break;
}
}
start = s;
// Format argument.
PAF(writer, spec).visit(arg);
}
write(writer, start, s);
}
}// namespace internal
} // namespace fmt
#endif

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@ -1,4 +1,6 @@
#include "fmt/format.h" #include "fmt/format.h"
#include "fmt/printf_formatter.h"
#include <iostream> #include <iostream>
// A custom argument formatter that doesn't print `-` for floating-point values // A custom argument formatter that doesn't print `-` for floating-point values
@ -17,6 +19,22 @@ class CustomArgFormatter :
} }
}; };
// A custom argument formatter that doesn't print `-` for floating-point values
// rounded to 0.
class CustomPAF : public fmt::internal::ArgFormatterBase<CustomPAF, char>
{
public:
CustomPAF(fmt::BasicWriter<char> &w, fmt::FormatSpec &s):
fmt::internal::ArgFormatterBase<CustomPAF, char>(w, s) {}
void visit_double(double value) {
if (round(value * pow(10, spec().precision())) == 0)
value = 0;
fmt::internal::ArgFormatterBase<CustomPAF, char>::visit_double(value);
}
};
std::string custom_format(const char *format_str, fmt::ArgList args) { std::string custom_format(const char *format_str, fmt::ArgList args) {
fmt::MemoryWriter writer; fmt::MemoryWriter writer;
// Pass custom argument formatter as a template arg to BasicFormatter. // Pass custom argument formatter as a template arg to BasicFormatter.
@ -28,7 +46,7 @@ FMT_VARIADIC(std::string, custom_format, const char *)
std::string printfer(const char* fstr, fmt::ArgList args){ std::string printfer(const char* fstr, fmt::ArgList args){
fmt::MemoryWriter writer; fmt::MemoryWriter writer;
fmt::internal::PrintfFormatter<char> pfer(args); fmt::internal::PrintfFormatter<char, CustomPAF> pfer(args);
pfer.format(writer,fstr); pfer.format(writer,fstr);
return writer.str(); return writer.str();
} }
@ -38,4 +56,5 @@ FMT_VARIADIC(std::string, printfer, const char*);
int main() { int main() {
std::cout << custom_format("custom: {:.2f}", -0.000001) << std::endl; std::cout << custom_format("custom: {:.2f}", -0.000001) << std::endl;
std::cout << printfer("printf: %.2f", -0.0001) << std::endl; std::cout << printfer("printf: %.2f", -0.0001) << std::endl;
} }

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@ -30,7 +30,7 @@
// Include format.cc instead of format.h to test implementation-specific stuff. // Include format.cc instead of format.h to test implementation-specific stuff.
#include "fmt/format.cc" #include "fmt/format.cc"
#include "fmt/printf_formatter.h"
#include <algorithm> #include <algorithm>
#include <cstring> #include <cstring>