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→‎{{header|C++}}: Prefer C++17's std::optional over boost::optional since most modern compilers fully support C++17, but keep boost::optional as a blurb

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rosettacode>CMM87

Revision as of 22:08, 2 August 2021 (view source) Shuisman (talk \| contribs) m (→‎{{header\|Mathematica}}) ← Older edit		Revision as of 05:14, 5 August 2021 (view source) rosettacode>CMM87 (→‎{{header\|C++}}: Prefer C++17's std::optional over boost::optional since most modern compilers fully support C++17, but keep boost::optional as a blurb) Newer edit →
Line 389: }</lang> ~~boost~~std::optional is available since C++17 (or Boost's boost::optional via boost/optional.hpp for earlier standards) for cases where the programmer wishes to pass by value, but still support a null value. <lang cpp> #include <boost/optional.hpp>▼ #include <iostream> ▲#include <~~boost/~~optional~~.hpp~~> ~~boost~~std::optional<int> maybeInt() int main() { ~~boost~~std::optional<int> maybe = maybeInt(); if(!maybe)