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Why exactly is eval evil?

...nic or other) pointers restartable exceptions self-modifying code ...and a cast of thousands. If you find yourself having to use any of these powerful, potentially dangerous tools ask yourself three times "why?" in a chain. For example: "Why do I have to use eval?" "Because of foo." "Why ...
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What's the meaning of interface{}?

...mment by @NickCraig-Wood. interface{} can point to anything and you need a cast/type assertion to use it. package main import ( . "fmt" "strconv" ) var c = cat("Fish") var d = dog("Bone") func main() { var i interface{} = c switch i.(type) { case cat: c.Eat() // Fish...
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Reference: Comparing PHP's print and echo

...print. print e, when evaluated: evaluates its single argument e and type-casts the resulting value to a string s. (Thus, print e is equivalent to print (string) e.) Streams the string s to the output buffer (which eventually will be streamed to the standard output). Evaluates to the integer 1. D...
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Using a ListAdapter to fill a LinearLayout inside a ScrollView layout

...nt position, long id) { // You can just use listView instead of parent casted to ListView. if (position >= ((ListView) parent).getHeaderViewsCount()) { // Note the usage of getItemAtPosition() instead of adapter's getItem() because // the latter does not take into account the ...
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The new keyword “auto”; When should it be used to declare a variable type? [duplicate]

...bdas can't be spelled, so auto f = []... is good style. The alternative is casting to std::function but that comes with overhead. I can't really conceive of an "abuse" of auto. The closest I can imagine is depriving yourself of an explicit conversion to some significant type -- but you wouldn't use...
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What is Rack middleware?

...mment about it being a way to filter requests probably comes from the RailsCast episode 151: Rack Middleware screen cast. Rack middleware evolved out of Rack and there is a great intro at Introduction to Rack middleware. There's an intro to middleware on Wikipedia here. ...
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When to use std::forward to forward arguments?

... } std::string to_string (void) const { auto address = static_cast<const void*>(this); std::stringstream ss; ss << address; return "BankAccount(" + ss.str() + ", cash $" + std::to_string(cash) + ")"; } }; template<typename T, typename Account&...
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Is a `=default` move constructor equivalent to a member-wise move constructor?

...as rvalue reference type T&&, it is direct-initialized with static_cast(x.m); otherwise, the base or member is direct-initialized with the corresponding base or member of x. Virtual base class subobjects shall be initialized only once by the implicitly-defined copy/move construct...
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How to store arrays in MySQL?

... AS pfs_person_name, cast(concat('[', group_concat(json_quote(fruit_name) ORDER BY fruit_name SEPARATOR ','), ']') as json) AS pfs_fruit_name_array FROM person INNER JOIN person_fruit ON person.person_id = person_fruit.pf_person ...
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C++ performance challenge: integer to std::string conversion

...e method, such as different stringstream implementations or boost::lexical_cast. It does not, however, make sense when asking for new code, a specialized algorithm, to do this. The reason is that int2string will always involve heap allocation from std::string and if we are trying to squeeze the last...