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Remove warnings from to_static_string

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This commit is contained in:
Krystian Stasiowski
2020-02-27 17:29:35 -05:00
parent bbbc8a6290
commit 315a9fd087
1 changed files with 26 additions and 12 deletions
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38
include/boost/static_string/static_string.hpp
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@ -475,6 +475,10 @@ inline
static_string<N> static_string<N>
to_static_string_float_impl(double value) noexcept to_static_string_float_impl(double value) noexcept
{ {
// we have to assume here that no reasonable implementation
// will require more than 2^63 chars to represent a float value.
const long long narrow =
static_cast<long long>(N);
// extra one needed for null terminator // extra one needed for null terminator
char buffer[N + 1]; char buffer[N + 1];
// we know that a formatting error will not occur, so // we know that a formatting error will not occur, so
@ -486,7 +490,8 @@ to_static_string_float_impl(double value) noexcept
const int reserved_count = const int reserved_count =
(std::max)(2, count_digits( (std::max)(2, count_digits(
std::numeric_limits<double>::max_exponent10)) + 4; std::numeric_limits<double>::max_exponent10)) + 4;
const int precision = N > reserved_count ? N - reserved_count : 0; const int precision = narrow > reserved_count ?
N - reserved_count : 0;
// switch to scientific notation // switch to scientific notation
std::snprintf(buffer, N + 1, "%.*e", precision, value); std::snprintf(buffer, N + 1, "%.*e", precision, value);
} }
@ -499,6 +504,10 @@ inline
static_string<N> static_string<N>
to_static_string_float_impl(long double value) noexcept to_static_string_float_impl(long double value) noexcept
{ {
// we have to assume here that no reasonable implementation
// will require more than 2^63 chars to represent a float value.
const long long narrow =
static_cast<long long>(N);
// extra one needed for null terminator // extra one needed for null terminator
char buffer[N + 1]; char buffer[N + 1];
// snprintf returns the number of characters // snprintf returns the number of characters
@ -512,7 +521,8 @@ to_static_string_float_impl(long double value) noexcept
const int reserved_count = const int reserved_count =
(std::max)(2, count_digits( (std::max)(2, count_digits(
std::numeric_limits<long double>::max_exponent10)) + 4; std::numeric_limits<long double>::max_exponent10)) + 4;
const int precision = N > reserved_count ? N - reserved_count : 0; const int precision = narrow > reserved_count ?
N - reserved_count : 0;
// switch to scientific notation // switch to scientific notation
std::snprintf(buffer, N + 1, "%.*Le", precision, value); std::snprintf(buffer, N + 1, "%.*Le", precision, value);
} }
@ -525,6 +535,10 @@ inline
static_wstring<N> static_wstring<N>
to_static_wstring_float_impl(double value) noexcept to_static_wstring_float_impl(double value) noexcept
{ {
// we have to assume here that no reasonable implementation
// will require more than 2^63 chars to represent a float value.
const long long narrow =
static_cast<long long>(N);
// extra one needed for null terminator // extra one needed for null terminator
wchar_t buffer[N + 1]; wchar_t buffer[N + 1];
// swprintf returns a negative number if it can't // swprintf returns a negative number if it can't
@ -536,18 +550,16 @@ to_static_wstring_float_impl(double value) noexcept
// implementations. // implementations.
const long long num_written = const long long num_written =
std::swprintf(buffer, N + 1, L"%f", value); std::swprintf(buffer, N + 1, L"%f", value);
// we have to assume here that no reasonable implementation
// will require more than 2^63 chars to represent a float
// value.
if (num_written < 0 || if (num_written < 0 ||
num_written > static_cast<long long>(N)) num_written > narrow)
{ {
// the + 4 is for the decimal, 'e', // the + 4 is for the decimal, 'e',
// its sign, and the sign of the integral portion // its sign, and the sign of the integral portion
const int reserved_count = const int reserved_count =
(std::max)(2, count_digits( (std::max)(2, count_digits(
std::numeric_limits<double>::max_exponent10)) + 4; std::numeric_limits<double>::max_exponent10)) + 4;
const int precision = N > reserved_count ? N - reserved_count : 0; const int precision = narrow > reserved_count ?
N - reserved_count : 0;
// switch to scientific notation // switch to scientific notation
std::swprintf(buffer, N + 1, L"%.*e", precision, value); std::swprintf(buffer, N + 1, L"%.*e", precision, value);
} }
@ -560,6 +572,10 @@ inline
static_wstring<N> static_wstring<N>
to_static_wstring_float_impl(long double value) noexcept to_static_wstring_float_impl(long double value) noexcept
{ {
// we have to assume here that no reasonable implementation
// will require more than 2^63 chars to represent a float value.
const long long narrow =
static_cast<long long>(N);
// extra one needed for null terminator // extra one needed for null terminator
wchar_t buffer[N + 1]; wchar_t buffer[N + 1];
// swprintf returns a negative number if it can't // swprintf returns a negative number if it can't
@ -571,18 +587,16 @@ to_static_wstring_float_impl(long double value) noexcept
// implementations. // implementations.
const long long num_written = const long long num_written =
std::swprintf(buffer, N + 1, L"%Lf", value); std::swprintf(buffer, N + 1, L"%Lf", value);
// we have to assume here that no reasonable implementation
// will require more than 2^63 chars to represent a float
// value.
if (num_written < 0 || if (num_written < 0 ||
num_written > static_cast<long long>(N)) num_written > narrow)
{ {
// the + 4 is for the decimal, 'e', // the + 4 is for the decimal, 'e',
// its sign, and the sign of the integral portion // its sign, and the sign of the integral portion
const int reserved_count = const int reserved_count =
(std::max)(2, count_digits( (std::max)(2, count_digits(
std::numeric_limits<long double>::max_exponent10)) + 4; std::numeric_limits<long double>::max_exponent10)) + 4;
const int precision = N > reserved_count ? N - reserved_count : 0; const int precision = narrow > reserved_count ?
N - reserved_count : 0;
// switch to scientific notation // switch to scientific notation
std::swprintf(buffer, N + 1, L"%.*Le", precision, value); std::swprintf(buffer, N + 1, L"%.*Le", precision, value);
} }