String Utilities

Classes and concepts for string manipulation and formatting. More...

Concepts
concept	toy::StringLike
	Concept satisfied when T exposes size() as size_t and c_str() as a pointer to null-terminated characters.

Classes
class	toy::CStringView
	Non-owning string view class for C-style strings. More...
class	toy::FixedString< allocatedSize >
	Template string class with fixed-size character buffer. More...
class	toy::FormatString< Args >
	Wrapper around a toy::CStringView pattern with consteval validation of placeholders. More...
class	toy::OStringStream< StringType >
	Output stream that appends formatted values into a toy::StringLike backend. More...
class	toy::StringFixedStorage< AllocatedSize >
	Fixed-size character storage with a tracked length and implicit null terminator at data()[size()]. More...

Enumerations
enum class	toy::FormatPatternValidationError {   toy::FormatPatternValidationError::none , toy::FormatPatternValidationError::unmatchedBrace , toy::FormatPatternValidationError::invalidContent , toy::FormatPatternValidationError::mixedPlaceholders ,   toy::FormatPatternValidationError::argCountMismatch , toy::FormatPatternValidationError::indexOutOfRange }
	Result of validating a format pattern against an expected argument count. More...

Functions
constexpr FormatPatternValidationError	toy::anonymous_namespace{format_pattern.inl}::validateFormatImpl (const CStringView &string, size_t argCount) noexcept
	Validates auto-indexed {} and positional {N} placeholders for argCount arguments.
constexpr FormatPatternValidationError	toy::validateFormatPattern (const CStringView &string, size_t argCount) noexcept
	Validates auto-indexed {} and positional {N} placeholders for argCount arguments.

Detailed Description

Classes and concepts for string manipulation and formatting.

This group contains all string-related types and utilities in the core module:

Key Features

• Zero or minimal dynamic allocation
• Constexpr support where possible
• Exception safety (noexcept operations)
• Type safety through C++20 concepts
• Cross-platform compatibility

Enumeration Type Documentation

FormatPatternValidationError

enum class toy::FormatPatternValidationError

strong

Result of validating a format pattern against an expected argument count.

Enumerator
none	Pattern is valid for the given argument count.
unmatchedBrace	Stray or incomplete { / } (not {{, }}, {}, or {N}).
invalidContent	Positional {N…} not closed by }, or disallowed characters after the index.
mixedPlaceholders	Mixed auto {} and positional {N} in one pattern.
argCountMismatch	Placeholder count vs expected argument count mismatch (including empty pattern with arguments).
indexOutOfRange	Positional index out of range or overflow while parsing digits.

Function Documentation

validateFormatImpl()

FormatPatternValidationError toy::anonymous_namespace{format_pattern.inl}::validateFormatImpl ( const CStringView & string, size_t argCount )

nodiscardconstexprnoexcept

Validates auto-indexed {} and positional {N} placeholders for argCount arguments.

Parameters

string	Pattern to scan.
argCount	Number of format arguments.

Returns

FormatPatternValidationError::none when the pattern is valid; otherwise the first validation error encountered.

Note

Internal implementation for validateFormatPattern; not part of the public API.

validateFormatPattern()

FormatPatternValidationError toy::validateFormatPattern ( const CStringView & string, size_t argCount )

nodiscardconstexprnoexcept

Validates auto-indexed {} and positional {N} placeholders for argCount arguments.

Parameters

string	Pattern to scan.
argCount	Number of format arguments.

Returns

Error code; FormatPatternValidationError::none when the pattern is consistent with argCount.