diff --git a/octa/algorithm.hh b/octa/algorithm.hh
index f483e73..cd74410 100644
--- a/octa/algorithm.hh
+++ b/octa/algorithm.hh
@@ -418,7 +418,7 @@ private:
     octa::FunctionMakeDefaultConstructible<F> p_func;
 
 public:
-    MapRange(): p_range(), p_func() {}
+    MapRange() = delete;
     MapRange(const T &range, const F &func):
         p_range(range), p_func(func) {}
     MapRange(const MapRange &it):
@@ -514,8 +514,7 @@ private:
     }
 
 public:
-    FilterRange(): p_range(), p_pred() {}
-
+    FilterRange() = delete;
     template<typename P>
     FilterRange(const T &range, const P &pred): p_range(range),
     p_pred(pred) {
diff --git a/octa/internal/hashtable.hh b/octa/internal/hashtable.hh
index a5d01e4..abbe062 100644
--- a/octa/internal/hashtable.hh
+++ b/octa/internal/hashtable.hh
@@ -57,7 +57,7 @@ private:
         if (p_beg != p_end) p_node = p_beg[0];
     }
 public:
-    HashRange(): p_beg(), p_end(), p_node() {}
+    HashRange() = delete;
     HashRange(const HashRange &v): p_beg(v.p_beg), p_end(v.p_end),
         p_node(v.p_node) {}
     HashRange(Chain **beg, Chain **end): p_beg(beg), p_end(end), p_node() {
@@ -107,7 +107,7 @@ private:
     using Chain = octa::detail::HashChain<T>;
     Chain *p_node;
 public:
-    BucketRange(): p_node() {}
+    BucketRange() = delete;
     BucketRange(Chain *node): p_node(node) {}
     BucketRange(const BucketRange &v): p_node(v.p_node) {}
 
diff --git a/octa/range.hh b/octa/range.hh
index 1c77535..ab5bcd4 100644
--- a/octa/range.hh
+++ b/octa/range.hh
@@ -254,14 +254,14 @@ private:
 public:
     using Range = T;
 
-    RangeHalf(): p_range() {}
-
+    RangeHalf() = delete;
     RangeHalf(const T &range): p_range(range) {}
 
     template<typename U, typename = octa::EnableIf<
         octa::IsConvertible<U, T>::value
     >> RangeHalf(const RangeHalf<U> &half): p_range(half.p_range) {}
 
+    RangeHalf(const RangeHalf &half): p_range(half.p_range) {}
     RangeHalf(RangeHalf &&half): p_range(octa::move(half.p_range)) {}
 
     RangeHalf &operator=(const RangeHalf &half) {
@@ -481,14 +481,18 @@ template<typename V, typename R = V &, typename S = octa::Size,
 
 template<typename T>
 struct HalfRange: InputRange<HalfRange<T>,
-    RangeCategory<T>, RangeValue<T>, RangeReference<T>, RangeSize<T>,
-    RangeDifference<T>
+    RangeCategory<typename T::Range>,
+    RangeValue<typename T::Range>,
+    RangeReference<typename T::Range>,
+    RangeSize<typename T::Range>,
+    RangeDifference<typename T::Range>
 > {
 private:
+    using Rtype = typename T::Range;
     T p_beg;
     T p_end;
 public:
-    HalfRange(): p_beg(), p_end() {}
+    HalfRange() = delete;
     HalfRange(const HalfRange &range): p_beg(range.p_beg),
         p_end(range.p_end) {}
     HalfRange(HalfRange &&range): p_beg(octa::move(range.p_beg)),
@@ -527,8 +531,8 @@ public:
         return p_end.next();
     }
 
-    RangeReference<T> front() const { return *p_beg; }
-    RangeReference<T> back() const { return *(p_end - 1); }
+    RangeReference<Rtype> front() const { return *p_beg; }
+    RangeReference<Rtype> back() const { return *(p_end - 1); }
 
     bool equals_front(const HalfRange &range) const {
         return p_beg == range.p_beg;
@@ -537,27 +541,28 @@ public:
         return p_end == range.p_end;
     }
 
-    RangeDifference<T> distance_front(const HalfRange &range) const {
+    RangeDifference<Rtype> distance_front(const HalfRange &range) const {
         return range.p_beg - p_beg;
     }
-    RangeDifference<T> distance_back(const HalfRange &range) const {
+    RangeDifference<Rtype> distance_back(const HalfRange &range) const {
         return range.p_end - p_end;
     }
 
-    RangeSize<T> size() const { return p_end - p_beg; }
+    RangeSize<Rtype> size() const { return p_end - p_beg; }
 
-    HalfRange<T> slice(RangeSize<T> start, RangeSize<T> p_end) const {
-        return HalfRange<T>(p_beg + start, p_beg + p_end);
+    HalfRange<Rtype>
+    slice(RangeSize<Rtype> start, RangeSize<Rtype> p_end) const {
+        return HalfRange<Rtype>(p_beg + start, p_beg + p_end);
     }
 
-    RangeReference<T> operator[](RangeSize<T> idx) const {
+    RangeReference<Rtype> operator[](RangeSize<Rtype> idx) const {
         return p_beg[idx];
     }
 
-    void put(const RangeValue<T> &v) {
+    void put(const RangeValue<Rtype> &v) {
         p_beg.range().put(v);
     }
-    void put(RangeValue<T> &&v) {
+    void put(RangeValue<Rtype> &&v) {
         p_beg.range().put(octa::move(v));
     }
 };
@@ -574,12 +579,9 @@ private:
     T p_range;
 
 public:
-    ReverseRange(): p_range() {}
-
+    ReverseRange() = delete;
     ReverseRange(const T &range): p_range(range) {}
-
     ReverseRange(const ReverseRange &it): p_range(it.p_range) {}
-
     ReverseRange(ReverseRange &&it): p_range(octa::move(it.p_range)) {}
 
     ReverseRange &operator=(const ReverseRange &v) {
@@ -652,12 +654,9 @@ private:
     T p_range;
 
 public:
-    MoveRange(): p_range() {}
-
+    MoveRange() = delete;
     MoveRange(const T &range): p_range(range) {}
-
     MoveRange(const MoveRange &it): p_range(it.p_range) {}
-
     MoveRange(MoveRange &&it): p_range(octa::move(it.p_range)) {}
 
     MoveRange &operator=(const MoveRange &v) {
@@ -721,7 +720,7 @@ public:
 
 template<typename T>
 struct NumberRange: InputRange<NumberRange<T>, ForwardRangeTag, T, T> {
-    NumberRange(): p_a(0), p_b(0), p_step(0) {}
+    NumberRange() = delete;
     NumberRange(const NumberRange &it): p_a(it.p_a), p_b(it.p_b),
         p_step(it.p_step) {}
     NumberRange(T a, T b, T step = T(1)): p_a(a), p_b(b),
@@ -753,7 +752,7 @@ NumberRange<T> range(T v) {
 
 template<typename T>
 struct PointerRange: InputRange<PointerRange<T>, FiniteRandomAccessRangeTag, T> {
-    PointerRange(): p_beg(nullptr), p_end(nullptr) {}
+    PointerRange() = delete;
     PointerRange(T *beg, T *end): p_beg(beg), p_end(end) {}
     PointerRange(T *beg, octa::Size n): p_beg(beg), p_end(beg + n) {}
 
@@ -884,7 +883,7 @@ private:
     Rsize p_index;
 
 public:
-    EnumeratedRange(): p_range(), p_index(0) {}
+    EnumeratedRange() = delete;
 
     EnumeratedRange(const T &range): p_range(range), p_index(0) {}
 
@@ -954,7 +953,7 @@ private:
     T p_range;
     RangeSize<T> p_remaining;
 public:
-    TakeRange(): p_range(), p_remaining(0) {}
+    TakeRange() = delete;
     TakeRange(const T &range, RangeSize<T> rem): p_range(range),
         p_remaining(rem) {}
     TakeRange(const TakeRange &it): p_range(it.p_range),
@@ -1008,7 +1007,7 @@ private:
     T p_range;
     RangeSize<T> p_chunksize;
 public:
-    ChunksRange(): p_range(), p_chunksize(0) {}
+    ChunksRange() = delete;
     ChunksRange(const T &range, RangeSize<T> chs): p_range(range),
         p_chunksize(chs) {}
     ChunksRange(const ChunksRange &it): p_range(it.p_range),
diff --git a/octa/stream.hh b/octa/stream.hh
index b02ab1a..20bcadf 100644
--- a/octa/stream.hh
+++ b/octa/stream.hh
@@ -63,7 +63,7 @@ template<typename T>
 struct StreamRange<T, true>: InputRange<
     StreamRange<T>, octa::InputRangeTag, T, T, octa::Size, StreamOffset
 > {
-    StreamRange(): p_stream(), p_size(0) {}
+    StreamRange() = delete;
     StreamRange(Stream &s): p_stream(&s), p_size(s.size()) {}
     StreamRange(const StreamRange &r): p_stream(r.p_stream), p_size(r.p_size) {}
 
diff --git a/octa/string.hh b/octa/string.hh
index 682b258..cca8968 100644
--- a/octa/string.hh
+++ b/octa/string.hh
@@ -22,7 +22,7 @@ template<typename T>
 struct StringRangeBase: InputRange<
     StringRangeBase<T>, FiniteRandomAccessRangeTag, T
 > {
-    StringRangeBase(): p_beg(nullptr), p_end(nullptr) {}
+    StringRangeBase() = delete;
     StringRangeBase(T *beg, T *end): p_beg(beg), p_end(end) {}
     StringRangeBase(T *beg, octa::Size n): p_beg(beg), p_end(beg + n) {}
     /* TODO: traits for utf-16/utf-32 string lengths, for now assume char */