This commit is contained in:
Thibault Kruse 2016-04-17 13:14:51 +02:00
parent 1863a750c0
commit e910836f3b

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@ -5724,13 +5724,13 @@ Such as on an ABI (link) boundary.
};
class D2 : public Device {
// ... differnt data ...
// ... different data ...
void write(span<const char> outbuf) override;
void read(span<char> inbuf) override;
};
A user can now use `D1`s and `D2`s interrchangeably through the interface provided by `Device`.
A user can now use `D1`s and `D2`s interchangeably through the interface provided by `Device`.
Furthermore, we can update `D1` and `D2` in a ways that are not binarily compatible with older versions as long as all access goes through `Device`.
##### Enforcement
@ -6730,7 +6730,7 @@ Readability. Convention. Reusability. Support for generic code
return os << /* class members here */;
}
By itself, `cout_my_class` would be OK, but it is not usable/composabe with code that rely on the `<<` convention for output:
By itself, `cout_my_class` would be OK, but it is not usable/composable with code that rely on the `<<` convention for output:
My_class var { /* ... */ };
// ...
@ -10854,7 +10854,7 @@ Let cleanup actions on the unwinding path be handled by [RAII](#Re-raii).
This code is messy.
There could be a leak from the naked pointer in the `try` block.
Not all exceptiones are handled.
Not all exceptions are handled.
`deleting` an object that failed to construct is almost certainly a mistake.
Better:
@ -10901,8 +10901,8 @@ Even without exceptions, [RAII](#Re-raii) is usually the best and most systemati
##### Note
Error handling using exceptions is the only complete and systematic way of handling non-local errors in C++.
In particular, non-intrusively signalling failure to construct an object requires an exception.
Signalling errors in a way that cannot be ignored requires exceptions.
In particular, non-intrusively signaling failure to construct an object requires an exception.
Signaling errors in a way that cannot be ignored requires exceptions.
If you can't use exceptions, simulate their use as best you can.
A lot of fear of exceptions is misguided.
@ -11078,7 +11078,7 @@ and to avoid confusion with other uses of `std::pair`.
###### Example
In general, you must clean up before an eror exit.
In general, you must clean up before an error exit.
This can be messy:
std::pair<int,error_indicator> user()
@ -11108,7 +11108,7 @@ This can be messy:
}
Simulating RAII can be non-trivial, especially in functions with multiple resources and multiple possible errors.
A not uncommon technique is to gather cleanup at the end of the function to avoid repetittion:
A not uncommon technique is to gather cleanup at the end of the function to avoid repetition:
std::pair<int,error_indicator> user()
{
@ -11139,7 +11139,7 @@ A not uncommon technique is to gather cleanup at the end of the function to avoi
}
The larger the function, the more tempting this technique becomes.
Aso, the larger the program becomes the harder it is to apply an error-indicator-based error handling strategy systematically.
Also, the larger the program becomes the harder it is to apply an error-indicator-based error handling strategy systematically.
We [prefer exception-based error handling](#Re-throw) and recommend [keeping functions short](#Rf-single).
@ -11164,7 +11164,7 @@ See also [Simulating RAII](#Re-no-throw-raii).
##### Note
C-stye error handling is based on the global variable `errno`, so it is essentially impossible to avoid this style completely.
C-style error handling is based on the global variable `errno`, so it is essentially impossible to avoid this style completely.
##### Enforcement
@ -12025,9 +12025,9 @@ In general, passing function objects gives better performance than passing point
auto y = find_if(v, [](double x) { return x>7; }); // function object: carries the needed data
auto z = find_if(v, Greater_than<double>(7)); // function object: carries the needed data
You can, of course, gneralize those functions using `auto` or (when and where available) concepts. For example:
You can, of course, generalize those functions using `auto` or (when and where available) concepts. For example:
auto y1 = find_if(v, [](Ordered x) { return x>7; }); // reruire an ordered type
auto y1 = find_if(v, [](Ordered x) { return x>7; }); // require an ordered type
auto z1 = find_if(v, [](auto x) { return x>7; }); // hope that the type has a >
##### Note
@ -12215,7 +12215,7 @@ Flag uses where an explicitly specialized type exactly matches the types of the
X(X&&); // move
X& operator=(X&&);
~X();
// ... no moreconstructors ...
// ... no more constructors ...
};
X x {1}; // fine
@ -12247,7 +12247,7 @@ Semiregular requires default constructible.
}
namespace T0 {
bool operator==(int, Bad::S) { cout << "T0\n"; return true; } // compate to int
bool operator==(int, Bad::S) { cout << "T0\n"; return true; } // compare to int
void test()
{