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/*
*/
#pragma once
template<typename T>
class slice
{
T* m_first;
unsigned int m_len;
public:
slice():
m_first(nullptr),
m_len(0)
{}
slice(const ::std::vector<T>& v):
m_first(&v[0]),
m_len(v.size())
{}
slice(::std::vector<T>& v):
m_first(&v[0]),
m_len(v.size())
{}
slice(T* ptr, unsigned int len):
m_first(ptr),
m_len(len)
{}
::std::vector<T> to_vec() const {
return ::std::vector<T>(begin(), end());
}
unsigned int size() const {
return m_len;
}
T& operator[](unsigned int i) const {
assert(i < m_len);
return m_first[i];
}
slice<T> subslice(unsigned int ofs, unsigned int len) const {
assert(ofs < m_len);
assert(len <= m_len);
assert(ofs + len <= m_len);
return slice { m_first + ofs, len };
}
T* begin() const { return m_first; }
T* end() const { return m_first + m_len; }
T& front() const { return m_first[0]; }
T& back() const { return m_first[m_len-1]; }
};
template<typename T>
::std::ostream& operator<<(::std::ostream& os, slice<T> s) {
if( s.size() > 0 )
{
bool is_first = true;
for( const auto& i : s )
{
if(!is_first)
os << ", ";
is_first = false;
os << i;
}
}
return os;
}
namespace rust {
template<typename T>
class option
{
char m_data[ sizeof(T) ];
bool m_set;
void* data_ptr() { return m_data; }
const void* data_ptr() const { return m_data; }
public:
option(T ent):
m_set(true)
{
new (m_data) T(::std::move(ent));
}
option():
m_set(false)
{}
~option() {
if( m_set ) {
reinterpret_cast<T*>(data_ptr())->~T();
}
}
bool is_none() const { return !m_set; }
bool is_some() const { return m_set; }
const T& unwrap() const {
assert(is_some());
return *reinterpret_cast<const T*>(m_data);
}
void if_set(::std::function<void (const T&)> f) const {
if( m_set ) {
return f(m_data);
}
}
//template<typename U/*, class FcnSome, class FcnNone*/>
//U match(::std::function<U(const T&)> if_some, ::Std::function<U()> if_none) const {
// if( m_set ) {
// return if_some(m_data);
// }
// else {
// return if_none();
// }
//}
};
template<typename T>
class option<T&>
{
T* m_ptr;
public:
option(T& ent):
m_ptr(&ent)
{}
option():
m_ptr(nullptr)
{}
bool is_none() const { return m_ptr == nullptr; }
bool is_some() const { return m_ptr != nullptr; }
T& unwrap() const {
assert(is_some());
return *m_ptr;
}
void if_set(::std::function<void (const T&)> f) const {
if( m_ptr ) {
return f(*m_ptr);
}
}
};
template<typename T>
option<T> Some(T data) {
return option<T>( ::std::move(data) );
}
template<typename T>
option<T> None() {
return option<T>( );
}
#define IF_OPTION_SOME(bind, var, ...) { auto __v = (var); if( var.is_some() ) { auto bind = __v.unwrap(); (void)&bind; __VA_ARGS__ } }
};
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