Lameness Explained

OK, more than one person wanted explanations of The C++ <random> Lame List, so here are some of my thoughts, if only to save people searching elsewhere. Calling rand() is lame because it’s an LCG with horrible randomness properties, and we can do better. And if you’re not calling rand(), there’s no reason to call… Continue reading Lameness Explained

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The C++ <random> Lame List

Network programmers of a certain age may remember the Windows Sockets Lame List. I previously wrote a short “don’t-do-that-do-this” guide for modern C++ randomness, and I was recently reading another Reddit exchange featuring STL, author of many parts of Microsoft’s STL implementation, when it struck me that use of C++ <random> needs its own lame… Continue reading The C++ <random> Lame List

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Compile-time RNG tricks

(Start at the beginning of the series – and all the source can be found in my github repo) Compile-time random number generation is quite useful. For instance, we could generate GUIDs (version 4 UUIDs): namespace cx { struct guid_t { uint32_t data1; uint16_t data2; uint16_t data3; uint64_t data4; }; template constexpr guid_t guidgen() {… Continue reading Compile-time RNG tricks

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Compile-time counters, revisited

(Start at the beginning of the series – and all the source can be found in my github repo) Some time ago I read a blog post showing how to make a compile-time counter: a constexpr function that would return monotonically increasing integers. When I first read it I didn’t really take the time to… Continue reading Compile-time counters, revisited

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C++11 compile-time string hashing

(Start at the beginning of the series – and all the source can be found in my github repo) Now that I was used to writing C++11-style constexpr, I decided to try some compile-time string hashing. It turns out that FNV1 is very easy to express in a move-down-the-string recursive style: namespace detail { constexpr… Continue reading C++11 compile-time string hashing

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Floating-point maths, constexpr style

(Start at the beginning of the series – and all the source can be found in my github repo) To ease into constexpr programming I decided to tackle some floating-point maths functions. Disclaimer: I’m not a mathematician and this code has not been rigorously tested for numeric stability or convergence in general. I wrote it… Continue reading Floating-point maths, constexpr style

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Experimenting with constexpr

Since seeing Scott Schurr at C++Now in Aspen and hearing his talks about constexpr, it’s been on my list of things to try out, and recently I got around to it. With the release of Visual Studio 2015, Microsoft’s compiler now finally supports C++11 style constexpr (modulo some minor issues), so it’s a good time… Continue reading Experimenting with constexpr

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