int main(void)
{
// instantiates static members Foo<string>::ctr and Foo<string>::count
Foo<string> fs;
// all three objects share the same Foo<int>::ctr and Foo<int>::count
// members
Foo<int> fi1, fi2, fi3;
Foo<int> fi; // instantiates Foo<int> class and the static data member ctr
Foo<int>::count(); // instantiates Foo<int>::count
fi.count(); // uses Foo<int>::count
//Foo::count(); // error: which template instantiation?
return 0;
}
int main()
{
#if 0
// specialization stuff
Foo<string> fs;
fs.Bar(); // calls regular function Bar
Foo<int> fi;
fi.Bar(); // calls specialized function Bar
FooMan fm("toad", 123, 0.1);
FooMan fm2("toad", 123, 0.1);
if (fm == fm2) {
cout << "equal FooMan" << endl;
} else {
cout << "non equal FooMan" << endl;
}
cout << hash<FooMan>{}(fm) << endl;
cout << hash<FooMan>{}(fm2) << endl;
vector<int> vi = {1,2,3,4};
int x = 42;
string name = "dude";
cout << hash<string>{}(name) << endl;
cout << hash<int>{}(42) << endl;
cout << hash<int>{}(x) << endl;
// partial template class specialization
int i;
rem_ref<decltype(42)>::type a;
rem_ref<decltype(i)>::type b;
rem_ref<decltype(std::move(i))>::type c;
a = b = c = 43; // all are ints
cout << "a: " << a << endl;
cout << "b: " << b << endl;
cout << "c: " << c << endl;
#endif
#if 1
// variadic templates
int i = 0;
double d = 3.14;
string s4 = "how now";
// template parameter T is deduces from 1st parameter
foo(i, s4, 42, d); // three parameters in pack
foo(s4, 42, "hi"); // two
foo(d, s4); // one
foo("hi"); // zero empty pack
// test print variadic template
print(cout, i, d, s4);
//errorMsg(cout, i, d, s4); // calls appropriate overloaded version of debug_rep
#endif
#if 0 // forwarding
int it = 43;
f(42, it);
it = 43;
flip2(f, it, 42);
cout << "after call: " << it << endl;
it = 43;
flip2(f, 42, it); // now it will chg, T2 is a ref
cout << "after call: " << it << endl;
it = 43;
flip3(f2, it, 42); // now it will chg, T2 is a ref
cout << "after call: " << it << endl;
#endif
#if 0 // rvalues
string s1("hi"), s2;
s2 = std::move(string("bye!")); // move from rvalue
cout << s2 << endl;
s2 = std::move(s1); // s1 is indeterminate state after move
cout << s2 << endl;
g(42);
// these won't compile
//const int i = 43;
//const int& j = i;
//g(j);
#endif
#if 0
cout << compare(1,0) << endl;
string a = "hand", b = "bag";
cout << compare(b,b) << endl;
cout << compare("dou","bag") << endl;
const char *p;
const char *q;
char ppp[] = "aaa";
char qqq[] = "bbb";
p = &ppp[0];
q = &qqq[0];
cout << compare(p, q) << endl; // specialization version
vector<int> v1{1,2,3};
vector<int> v2{4,5,6};
cout << compare(v1, v2) << endl;
cout << compare(v2, v1) << endl;
cout << compare(1, 0) << endl;
cout << compare(0, 1) << endl;
cout << compare(1, 1) << endl;
int rc = 42;
rc = foo(&rc);
cout << rc << endl;
const char a2[4] = "bag";
const char b2[4] = "dog";
cout << compare(a2, b2) << endl;
cout << compare2(a2, b2) << endl;
cout << compare3(1,0) << endl;
cout << compare3("bat","man") << endl;
int aa = 2;
long bb = 1;
cout << FlexibleCompare(aa, bb) << endl;
#endif
#if 0
vector<int> vi{1,2,3};
vector<string> vs{"one","two","three"};
const vector<string> cvs{"four","five","six"};
auto &ii = fcn(vi.begin(), vi.end());
auto &ss = fcn(vs.begin(), vs.end());
// this one uses type traits
auto &css = fcn2(cvs.begin(), cvs.end());
#endif
test_blob();
#if 0
Foo<int> fi;
auto ct = Foo<int>::count();
cout << "ct: " << ct << endl;
ct = fi.count();
cout << "ct: " << ct << endl;
// demo customer deleter
double *p = new double(3.14);
DebugDelete d;
d(p);
int *ip = new int(42);
DebugDelete()(ip);
#endif
#if 0
// we can supply DebugDelete as the deleter to unique_ptr's
unique_ptr<int, DebugDelete> p2(new int(43), DebugDelete());
unique_ptr<string, DebugDelete> sp2(new string("dude"), DebugDelete());
shared_ptr<string> ps(new string("the dawg"), DeleteStringPtr);
shared_ptr<string> ps2(new string("homi"), my_deleter<string>);
// reset to different deleter at run-time -- only shared_ptr's not unique_ptr's
// looks like call to reset will call the original deleter first
ps2.reset(new string("wusup"), my_deleter2<string>);
#endif
#if 0
// template overloading
string s("hi");
cout << debug_rep(s) << endl;
cout << debug_rep(&s) << endl;
cout << debug_rep("hi world!") << endl;
char s2[] = "hello dude";
cout << debug_rep(s2) << endl;
#endif
}
