to_arithmetic

Functions that will convert a text representation of an arithmetic type to a value.

Converts from binary, octal, decimal and hex integrals, and decimal floating point types.

Supports conversion from char, wchar_t, char16_t and char32_t strings.

The numeric strings must not contain leading or trailing non-numeric characters. It is the responsibility of the user to

select the valid character range.

Integral types may be constexpr.

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to_arithmetic_status

An ETL enum type that defines the following enumeration values.

The are the values that may be set as the error code in to_arithmetic_result.

Valid

Invalid_Radix

Invalid_Format

Invalid_Float

Signed_To_Unsigned

Overflow

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to_arithmetic_result

The result type returned from etl::to_arithmetic.

template <typename TValue>

to_arithmetic_result

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Types

value_type TValue

error_type etl::to_arithmetic_status

unexpected_type etl::unexpected<etl::to_arithmetic_status>

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ETL_CONSTEXPR14

to_arithmetic_result()

Default constructor.

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ETL_CONSTEXPR14

to_arithmetic_result(const to_arithmetic_result& other)

Copy constructor.

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ETL_NODISCARD

ETL_CONSTEXPR14

bool has_value() const

Returns true if the result has a valid value.

If false then the value is undefined.

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ETL_NODISCARD

ETL_CONSTEXPR14

operator bool() const

Returns true if the result has a valid value.

If false then the value is undefined.

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ETL_NODISCARD

ETL_CONSTEXPR14

value_type value() const

Returns the value, if valid.

Otherwise undefined.

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ETL_NODISCARD

ETL_CONSTEXPR14

operator value_type() const

Returns the value, if valid.

Otherwise undefined.

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ETL_NODISCARD

ETL_CONSTEXPR14

error_type error() const

Returns the conversion status.

One of the following:-

Valid

Invalid_Radix

Invalid_Format

Invalid_Float

Signed_To_Unsigned

Overflow

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ETL_CONSTEXPR14

to_arithmetic_result& operator =(value_type value)

Assign from a value_type.

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ETL_CONSTEXPR14

to_arithmetic_result& operator =(unexpected_type status)

Assign from an unexpected_type.

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to_arithmetic

Convert a string to an integral or floating point value.

Supports:

etl::string_view (etl::basic_string_view<TChar>)

const pointer (to char, wchar_t, char16_t, char32_t) + length

etl::string, etl::wstring, etl::u16string or etl::u32string

template <typename TValue, typename TChar>

ETL_NODISCARD

ETL_CONSTEXPR14

etl::to_arithmetic_result<TValue> to_arithmetic(const etl::basic_string_view<TChar>& view)

Text to integral or floating point from view and default decimal radix.

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template <typename TValue, typename TChar>

ETL_NODISCARD

ETL_CONSTEXPR14

etl::to_arithmetic_result<TValue> to_arithmetic(etl::basic_string_view<TChar> view,

const etl::radix::value_type radix)

Text to integral from view and radix value type.

radix may be one of the following:-

etl::radix::binary

etl::radix::octal

etl::radix::decimal

etl::radix::hex

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ETL_NODISCARD

ETL_CONSTEXPR14

etl::to_arithmetic_result<TValue> to_arithmetic(const etl::basic_string_view<TChar>& view,

const etl::private_basic_format_spec::base_spec& spec)

Text to integral from view and radix format spec.

spec may be one of the following:-

etl::bin

etl::oct

etl::dec

etl::hex

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template <typename TValue, typename TChar>

ETL_NODISCARD

ETL_CONSTEXPR14

etl::to_arithmetic_result<TValue> to_arithmetic(const TChar* cp,

size_t length)

Text to integral or floating point from pointer, length and default decimal radix.

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template <typename TValue, typename TChar>

ETL_NODISCARD

ETL_CONSTEXPR14

etl::to_arithmetic_result<TValue> to_arithmetic(const TChar* cp,

size_t length,

const etl::radix::value_type radix)

Text to integral from pointer, length and radix value type.

radix may be one of the following:-

etl::radix::binary

etl::radix::octal

etl::radix::decimal

etl::radix::hex

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template <typename TValue, typename TChar>

ETL_NODISCARD

ETL_CONSTEXPR14

etl::to_arithmetic_result<TValue> to_arithmetic(const TChar* cp,

size_t length,

const etl::private_basic_format_spec::base_spec& spec)

Text to integral from pointer, length and radix format spec.

spec may be one of the following:-

etl::bin

etl::oct

etl::dec

etl::hex

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template <typename TValue, typename TChar>

ETL_NODISCARD

ETL_CONSTEXPR14

etl::to_arithmetic_result<TValue> to_arithmetic(const etl::ibasic_string<TChar>& str)

Text to integral or floating point from string and default decimal radix.

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template <typename TValue, typename TChar>

ETL_NODISCARD

ETL_CONSTEXPR14

etl::to_arithmetic_result<TValue> to_arithmetic(const etl::ibasic_string<TChar>& str,

const etl::radix::value_type radix)

Text to integral from string and radix value type.

radix may be one of the following:-

etl::radix::binary

etl::radix::octal

etl::radix::decimal

etl::radix::hex

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template <typename TValue, typename TChar>

ETL_NODISCARD

ETL_CONSTEXPR14

etl::to_arithmetic_result<TValue> to_arithmetic(const etl::ibasic_string<TChar>& str,

const etl::private_basic_format_spec::base_spec& spec)

Text to integral from string and radix format spec.

spec may be one of the following:-

etl::bin

etl::oct

etl::dec

etl::hex

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Non-member functions

template <typename T>

ETL_CONSTEXPR14 bool operator ==(const etl::to_arithmetic_result<T>& lhs,

const etl::to_arithmetic_result<T>& rhs)

Equality test for etl::to_arithmetic_result

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template <typename T, typename U>

ETL_CONSTEXPR14 bool operator ==(const etl::to_arithmetic_result<T>& lhs,

const U& rhs)

Equality test for etl::to_arithmetic_result

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template <typename T, typename U>

ETL_CONSTEXPR14 bool operator ==(const T& lhs,

const etl::to_arithmetic_result<U>& rhs)

Equality test for etl::to_arithmetic_result

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template <typename T>

ETL_CONSTEXPR14 bool operator !=(const etl::to_arithmetic_result<T>& lhs,

const etl::to_arithmetic_result<T>& rhs)

Inequality test for etl::to_arithmetic_result

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template <typename T, typename U>

ETL_CONSTEXPR14 bool operator !=(const etl::to_arithmetic_result<T>& lhs,

const U& rhs)

Inequality test for etl::to_arithmetic_result

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template <typename T, typename U>

ETL_CONSTEXPR14 bool operator !=(const T& lhs,

const etl::to_arithmetic_result<T>& rhs)

Inequality test for etl::to_arithmetic_result

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Examples

Valid conversions

const char* BinaryText("1010011");

const etl::string<3> OctalText("123");

const etl::string<4> DecimalText(" 83 ");

const etl::string<2> HexText("85");

const etl::string<2> FloatText("-123e5");

// From char pointer to binary text. Format spec radix.

int v1 = etl::to_arithmetic<int>(BinaryText, strlen(BinaryText), etl::bin);

// From char pointer from octal text string. Radix spec value.

int v2 = etl::to_arithmetic<int>(OctalText.c_str(), OctalText.size(), etl::radix::octal);

// From view of decimal text string. Default base 10 radix.

etl::string_view view(DecimalText.data() + 1, DecimalText.data() + 3);

int v3 = etl::to_arithmetic<int>(view);

// From hex string. Base 16 radix.

int v4 = etl::to_arithmetic<int>(HexText, 16);

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Invalid conversions

const etl::string<10> Text1("abcd");

const etl::string<10> Text2(" 83 ");

const etl::string<10> Text3("-83");

const etl::string<10> Text4("4294967296");

const etl::string<10> Text5("1.23E10000");

etl::to_arithmetic_result result;

result = etl::to_arithmetic<int32_t>(Text1, 5); // etl::to_arithmetic_status::Invalid_Radix

result = etl::to_arithmetic<int32_t>(Text1); // etl::to_arithmetic_status::Invalid_Format

result = etl::to_arithmetic<int32_t>(Text2); // etl::to_arithmetic_status::Invalid_Format

result = etl::to_arithmetic<uint32_t>(Text3); // etl::to_arithmetic_status::Signed_To_Unsigned

result = etl::to_arithmetic<int32_t>(Text4); // etl::to_arithmetic_status::Overflow

result = etl::to_arithmetic<float>(Text5); // etl::to_arithmetic_status::Overflow

to_arithmetic.h