例： const int max = 20； // max是常量表达式 const int maxx = max+1； //maxx是常量表达式 int litter = 10； //litter 不是常量表达式 const int sz = get-size（）； //sz 不是常量表达式 注释： litter 虽然是一个字面常量但是它的类型只是普通的类型int，所以不是常量表达式。 sz 虽然是一个常量（const）但是它的具体值...
First, use of const does not make it immediately clear whether the variable is usable in a constant expression or not. In some cases, we can figure it out fairly easily: int a { 5 }; // not const at all const int b { a }; // clearly not a constant expression (since initializer...
A non-formal description of a constant expression could be: Given compile time input, the constant expression can compute the result. For a variable, it's pretty straightforward. You set the value at compile time, you have the result at compile time. In C++ 14 (and also C++ 11 actually,...
};/*constexpr variable 'g_PERT_S1' must be initialized by a constant expression non-constexpr function 'data' cannot be used in a constant expression array(226): declared here*/constexprarray<ELPMPP02Pertubations, 4> g_PERT_S1/*ERROR HERE*/{ { { g_PERT_S1_1.data(), g_PERT_S1_...
begin1.csh: begin1.csh: 0:441(28): error: initializer of const variable `worldSunColor' must be a constant expression 0:442(32): error: initializer of const variable `worldHorizonColor' must be a constant expression 0:443(29): error: initializer of const variable `worldMoonColor' must ...
// Error! Not initializedintj=0;constexprintk=j+1;//Error! j not a constant expression ...
test.cpp:19:17: error:constexprvariable 'Data' must be initialized by a constant expression ...
例： const int max = 20； // max是常量表达式 const int maxx = max+1； //maxx是常量表达...
Defines an expression that can be evaluated at compile time. Such expressions can be used as non-type template arguments, array sizes, and in other contexts that require constant expressions. If you have a constant integral variable that isconstinitialized, or enumeration value, then it can be ...
D:\Projects\temp\demo\main.cpp(17,32): error C2131: expression did not evaluate to a constant [D:\Projects\temp\out\demo\demo.vcxproj] D:\Projects\temp\demo\main.cpp(17,21): message : failure was caused by a read of a variable outside its lifetime [D:\Projects\temp\out\demo\...