Embracing User-Defined Literals Safely
summary
Explains concrete rules and tradeoffs for C++ user-defined literals: four forms (cooked, raw, numeric-template, string-template), 12 cooked overloads, and when the compiler versus the library must parse or detect overflow. Gives working examples (temperature, IPv4, base‑3 parser, chrono units), shows pitfalls like negatives are not part of the literal and namespace lookup collisions, and recommends consteval in C++20 to force compile‑time errors. Demonstrates what to build, how it’s parsed, when it fails, and when factory functions or typedefs are safer.
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chapters (21)
- 0:00Intro
- 1:20Literal Examples
- 3:36Outline
- 4:44About me
- 6:27Book
- 8:49UserDefined Literals
- 9:39Why UserDefined Literals
- 11:38Common UserDefined Literals
- 14:25Other Restrictions
- 18:26Factory Functions
- 19:30UserDefined Literal
- 21:03syntactic sugar
- 22:27how to define
- 25:47namespaces
- 28:43cooked udl operators
- 37:39token example
- 42:27possible overloads
- 42:56cooked literals
- 47:48raw udl operators
- 51:05base3 udl
- 54:16base3 error detection
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