toml::parse_result class

The result of a parsing operation.

A parse_result is effectively a discriminated union containing either a toml::table or a toml::parse_error. Most member functions assume a particular one of these two states, and calling them when in the wrong state will cause errors (e.g. attempting to access the error object when parsing was successful).

parse_result result = toml::parse_file("config.toml");
if (result)
    do_stuff_with_a_table(result); //implicitly converts to table&
else
    std::cerr << "Parse failed:\n"sv << result.error() << "\n";

example output:

Parse failed:
Encountered unexpected character while parsing boolean; expected 'true', saw 'trU'
    (error occurred at line 1, column 13 of 'config.toml')

Getting node_views (operator[]) and using the iterator accessor functions (begin(), end() etc.) are unconditionally safe; when parsing fails these just return 'empty' values. A ranged-for loop on a failed parse_result is also safe since begin() and end() return the same iterator and will not lead to any dereferences and iterations.

Conditional availability

This type only exists when exceptions are disabled. Otherwise parse_result is just an alias for toml::table:

#if TOML_EXCEPTIONS
    using parse_result = table;
#else
    class parse_result final { // ...
#endif

Public types

using const_iterator = const_table_iterator: A BidirectionalIterator for iterating over const key-value pairs in a wrapped toml::table.
using iterator = table_iterator: A BidirectionalIterator for iterating over key-value pairs in a wrapped toml::table.

Constructors, destructors, conversion operators

operator bool() const explicit noexcept: Returns true if parsing succeeded.
operator const parse_error&() const explicit noexcept: Returns the internal toml::parse_error (const lvalue overload).
operator const toml::table&() const noexcept: Returns the internal toml::table (const lvalue overload).
operator parse_error&() explicit noexcept: Returns the internal toml::parse_error.
operator parse_error&&() explicit noexcept: Returns the internal toml::parse_error (rvalue overload).
operator toml::table&() noexcept: Returns the internal toml::table.
operator toml::table&&() noexcept: Returns the internal toml::table (rvalue overload).
parse_result(parse_result&& res) noexcept: Move constructor.
~parse_result() noexcept: Destructor.

Public functions

auto begin() → table_iterator noexcept: Returns an iterator to the first key-value pair in the wrapped table.
auto begin() const → const_table_iterator noexcept: Returns an iterator to the first key-value pair in the wrapped table.
auto cbegin() const → const_table_iterator noexcept: Returns an iterator to the first key-value pair in the wrapped table.
auto cend() const → const_table_iterator noexcept: Returns an iterator to one-past-the-last key-value pair in the wrapped table.
auto end() → table_iterator noexcept: Returns an iterator to one-past-the-last key-value pair in the wrapped table.
auto end() const → const_table_iterator noexcept: Returns an iterator to one-past-the-last key-value pair in the wrapped table.
auto error() & → parse_error& noexcept: Returns the internal toml::parse_error.
auto error() && → parse_error&& noexcept: Returns the internal toml::parse_error (rvalue overload).
auto error() const & → const parse_error& noexcept: Returns the internal toml::parse_error (const lvalue overload).
auto failed() const → bool noexcept: Returns true if parsing failed.
auto operator=(parse_result&& rhs) → parse_result& noexcept: Move-assignment operator.
auto operator[](string_view key) → node_view<node> noexcept: Gets a node_view for the selected key-value pair in the wrapped table.
auto operator[](string_view key) const → node_view<const node> noexcept: Gets a node_view for the selected key-value pair in the wrapped table (const overload).
auto operator[](std::wstring_view key) → node_view<node> noexcept: Gets a node_view for the selected key-value pair in the wrapped table.
auto operator[](std::wstring_view key) const → node_view<const node> noexcept: Gets a node_view for the selected key-value pair in the wrapped table (const overload).
auto succeeded() const → bool noexcept: Returns true if parsing succeeeded.
auto table() & → toml::table& noexcept: Returns the internal toml::table.
auto table() && → toml::table&& noexcept: Returns the internal toml::table (rvalue overload).
auto table() const & → const toml::table& noexcept: Returns the internal toml::table (const lvalue overload).

Friends

template <typename Char> auto operator<<(std::basic_ostream<Char>& os, const parse_result& result) → std::basic_ostream<Char>&: Prints the held error or table object out to a text stream.

Function documentation

table_iterator toml::parse_result::begin() noexcept

Returns an iterator to the first key-value pair in the wrapped table.

const_table_iterator toml::parse_result::begin() const noexcept

Returns an iterator to the first key-value pair in the wrapped table.

const_table_iterator toml::parse_result::cbegin() const noexcept

Returns an iterator to the first key-value pair in the wrapped table.

const_table_iterator toml::parse_result::cend() const noexcept

Returns an iterator to one-past-the-last key-value pair in the wrapped table.

table_iterator toml::parse_result::end() noexcept

Returns an iterator to one-past-the-last key-value pair in the wrapped table.

const_table_iterator toml::parse_result::end() const noexcept

Returns an iterator to one-past-the-last key-value pair in the wrapped table.

node_view<node> toml::parse_result::operator[](string_view key) noexcept

Gets a node_view for the selected key-value pair in the wrapped table.

Parameters
key	The key used for the lookup.
Returns	A view of the value at the given key if parsing was successful and a matching key existed, or an empty node view.

node_view<const node> toml::parse_result::operator[](string_view key) const noexcept

Gets a node_view for the selected key-value pair in the wrapped table (const overload).

Parameters
key	The key used for the lookup.
Returns	A view of the value at the given key if parsing was successful and a matching key existed, or an empty node view.

node_view<node> toml::parse_result::operator[](std::wstring_view key) noexcept

Gets a node_view for the selected key-value pair in the wrapped table.

Parameters
key	The key used for the lookup.
Returns	A view of the value at the given key if parsing was successful and a matching key existed, or an empty node view.

node_view<const node> toml::parse_result::operator[](std::wstring_view key) const noexcept

Gets a node_view for the selected key-value pair in the wrapped table (const overload).

Parameters
key	The key used for the lookup.
Returns	A view of the value at the given key if parsing was successful and a matching key existed, or an empty node view.