Higher-order functions in Modern C++: existing techniques and function_ref

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" summary

Covers practical higher-order patterns and proposes function_ref as a lightweight, non-owning callable reference implemented as a void plus function pointer type-erasure. Benchmarks (Google Benchmark, Simon Brand’s impl) show that function_ref is zero-cost when inlined* — matching template callables — while std::function pays large overhead (roughly an order of magnitude slower when inlined); without inlining function_ref is ~2x slower than templates but still faster than std::function. Notes: noexcept propagation, dangling-reference risk (does not extend lifetime).

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" chapters (52)

1. 0:00Introduction
2. 1:00Outline
3. 1:20Disclaimer
4. 1:54Assumptions
5. 2:07Higherorder functions
6. 2:30Example twice
7. 2:58Greater than
8. 4:48Signal
9. 6:21Bus
10. 7:55Overload
11. 9:09Use cases
12. 9:34Repetition
13. 9:59Integration test
14. 10:50UI example
15. 12:24Inverted control flow
16. 17:41Production example
17. 19:19Synchronicity
18. 19:42BoostFuture
19. 21:00enumeratetypes
20. 22:42the same obstruction
21. 23:07pros and cons
22. 24:08Left vs Right
23. 25:38Left Guard
24. 26:39Benchmarking
25. 26:56Iterators vs Highorder Functions
26. 28:11Filter Iterator
27. 28:40Highorder function
28. 29:11Highorder duration
29. 32:33Questions
30. 32:48pointers to functions
31. 33:27template parameters
32. 34:40city function
33. 35:38functionref
34. 37:21why use functionref
35. 38:12interface
36. 39:06use case example
37. 41:30packagecache example
38. 42:54state change callback
39. 44:04implementation
40. 45:02construction
41. 47:15invocation
42. 48:08no accept
43. 49:12the bad
44. 50:41conceptsper
45. 51:33benchmarks
46. 52:11template parameter
47. 52:31tests
48. 54:21conclusions
49. 55:30design decisions
50. 57:33assignment operator
51. 58:33reference wrapper
52. 59:28multifunctionref

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