Merge branch 'master' into jacobl.macbuild

This commit is contained in:
Jacob Langley
2017-02-07 10:26:30 -08:00
2 changed files with 64 additions and 22 deletions

View File

@@ -1,6 +1,6 @@
# <a name="main"></a>C++ Core Guidelines # <a name="main"></a>C++ Core Guidelines
February 1, 2017 February 6, 2017
Editors: Editors:
@@ -6562,11 +6562,49 @@ This a relatively rare use because implementation can often be organized into a
##### Reason ##### Reason
??? Without a using declaration, member functions in the derived class hide the entire inherited overload sets.
##### Example ##### Example, bad
??? #include <iostream>
class B {
public:
virtual int f(int i) { std::cout << "f(int): "; return i; }
virtual double f(double d) { std::cout << "f(double): "; return d; }
};
class D: public B {
public:
int f(int i) override { std::cout << "f(int): "; return i+1; }
};
int main()
{
D d;
std::cout << d.f(2) << '\n'; // prints "f(int): 3"
std::cout << d.f(2.3) << '\n'; // prints "f(int): 3"
}
##### Example, good
class D: public B {
public:
int f(int i) override { std::cout << "f(int): "; return i+1; }
using B::f; // exposes f(double)
};
##### Note
This issue affects both virtual and non-virtual member functions
For variadic bases, C++17 introduced a variadic form of the using-declaration,
template <class... Ts>
struct Overloader : Ts... {
using Ts::operator()...; // exposes operator() from every base
};
##### Enforcement
Diagnose name hiding
### <a name="Rh-final"></a>C.139: Use `final` sparingly ### <a name="Rh-final"></a>C.139: Use `final` sparingly
@@ -11659,16 +11697,16 @@ this can be a security risk.
##### Enforcement ##### Enforcement
Some is possible, do at least something. When possible, rely on tooling enforcement, but be aware that any tooling
There are commercial and open-source tools that try to address this problem, but static tools often have many false positives and run-time tools often have a significant cost. solution has costs and blind spots. Defense in depth (multiple tools, multiple
We hope for better tools. approaches) is particularly valuable here.
Help the tools: There are other ways you can mitigate the chance of data races:
* less global data * Avoid global data
* fewer `static` variables * Avoid `static` variables
* more use of stack memory (and don't pass pointers around too much) * More use of value types on the stack (and don't pass pointers around too much)
* more immutable data (literals, `constexpr`, and `const`) * More use of immutable data (literals, `constexpr`, and `const`)
### <a name="Rconc-data"></a>CP.3: Minimize explicit sharing of writable data ### <a name="Rconc-data"></a>CP.3: Minimize explicit sharing of writable data

View File

@@ -1,7 +1,9 @@
' '
0xFF0000 0xFF0000
0b0101'0101 0b0101'0101
10x
'14 '14
20x
2D 2D
2K 2K
2ndEdition 2ndEdition
@@ -69,6 +71,7 @@ CComPtr
cerr cerr
chrono chrono
cin cin
Clang's
class' class'
clib clib
Cline99 Cline99
@@ -492,6 +495,7 @@ toolchains
TotallyOrdered TotallyOrdered
TP TP
tradeoff tradeoff
TSAN
TSs TSs
tt tt
typeid typeid