diff --git a/docs/dev/clang-tidy-fixes-2026-04.md b/docs/dev/clang-tidy-fixes-2026-04.md
index ec44f4dcd..8af7344e6 100644
--- a/docs/dev/clang-tidy-fixes-2026-04.md
+++ b/docs/dev/clang-tidy-fixes-2026-04.md
@@ -101,7 +101,8 @@
 - [x] [modernize-avoid-c-arrays](https://clang.llvm.org/extra/clang-tidy/checks/modernize/avoid-c-arrays.html) (17)
   - _a.k.a._ [cppcoreguidelines-avoid-c-arrays](https://clang.llvm.org/extra/clang-tidy/checks/cppcoreguidelines/avoid-c-arrays.html)
   - [PR #745](https://github.com/Framework-R-D/phlex/pull/745)
-- [ ] [modernize-avoid-c-style-cast](https://clang.llvm.org/extra/clang-tidy/checks/modernize/avoid-c-style-cast.html) (82)
+- [x] [modernize-avoid-c-style-cast](https://clang.llvm.org/extra/clang-tidy/checks/modernize/avoid-c-style-cast.html) (82)
+  - [PR #771](https://github.com/Framework-R-D/phlex/pull/771)
 - [ ] [modernize-concat-nested-namespaces](https://clang.llvm.org/extra/clang-tidy/checks/modernize/concat-nested-namespaces.html) (1)
 - [x] [modernize-make-shared](https://clang.llvm.org/extra/clang-tidy/checks/modernize/make-shared.html) (1)
   - [PR #746](https://github.com/Framework-R-D/phlex/pull/746)
diff --git a/form/root_storage/root_rfield_read_container.cpp b/form/root_storage/root_rfield_read_container.cpp
index 1373e1e6d..72f84f797 100644
--- a/form/root_storage/root_rfield_read_container.cpp
+++ b/form/root_storage/root_rfield_read_container.cpp
@@ -79,8 +79,9 @@ namespace form::detail::experimental {
       createView(type);
     }
 
-    if (id >= (int)m_reader->GetNEntries())
+    if (id >= static_cast<int>(m_reader->GetNEntries())) {
       return false;
+    }
 
     //Using RNTupleView<> to read instead of reusing REntry gives us full schema evolution support: the ROOT feature that lets us read files with an old class version into a new class version's memory.
     auto buffer = m_view->GetField().CreateObject<void>(); //PHLEX gets ownership of this memory
diff --git a/form/storage/storage_reader.cpp b/form/storage/storage_reader.cpp
index 4e77811d5..d327cae77 100644
--- a/form/storage/storage_reader.cpp
+++ b/form/storage/storage_reader.cpp
@@ -147,8 +147,7 @@ namespace {
     if (components.empty()) {
       return false;
     }
-    for (auto const& [key, value] : components) {
-      (void)key;
+    for (auto const& [_, value] : components) {
       if (value != 0) {
         return false;
       }
@@ -356,8 +355,7 @@ std::vector<std::string> StorageReader::listIndices(
 
   std::vector<std::string> result;
   result.reserve(ordered.size());
-  for (auto const& [entry, index_string] : ordered) {
-    (void)entry;
+  for (auto const& [_, index_string] : ordered) {
     result.push_back(index_string);
   }
   return result;
diff --git a/phlex/model/index_generator.hpp b/phlex/model/index_generator.hpp
index cf856b21e..9e66a681e 100644
--- a/phlex/model/index_generator.hpp
+++ b/phlex/model/index_generator.hpp
@@ -79,7 +79,7 @@ namespace phlex {
         return *this;
       }
 
-      void operator++(int) { (void)++(*this); }
+      void operator++(int) { ++(*this); }
 
       value_type const& operator*() const noexcept { return coroutine_.promise().current_; }
       value_type const* operator->() const noexcept
diff --git a/phlex/utilities/resource_usage.cpp b/phlex/utilities/resource_usage.cpp
index fe98ceeb5..18111b3a0 100644
--- a/phlex/utilities/resource_usage.cpp
+++ b/phlex/utilities/resource_usage.cpp
@@ -26,9 +26,9 @@ namespace {
     auto const [secs, microsecs] = used.ru_utime;
     // ru_maxrss is a POSIX field inside a GCC __extension__ union in <sys/resource.h>;
     // no user-controlled alternative exists.
-    return {.elapsed_time = double(secs) + (double(microsecs) / 1e6),
+    return {.elapsed_time = static_cast<double>(secs) + (static_cast<double>(microsecs) / 1e6),
             // NOLINTNEXTLINE(cppcoreguidelines-pro-type-union-access)
-            .max_rss = double(used.ru_maxrss) / mem_denominator};
+            .max_rss = static_cast<double>(used.ru_maxrss) / mem_denominator};
   }
 }
 
diff --git a/plugins/python/src/configwrap.cpp b/plugins/python/src/configwrap.cpp
index ad4f6cb43..833822806 100644
--- a/plugins/python/src/configwrap.cpp
+++ b/plugins/python/src/configwrap.cpp
@@ -98,7 +98,7 @@ static PyObject* pcm_subscript(py_config_map* pycmap, PyObject* pykey)
         pyvalue = PyTuple_New(*cvalue_size);
         // We can use std::views::enumerate once the AppleClang C++ STL supports it.
         for (Py_ssize_t i = 0; i < *cvalue_size; ++i) {
-          PyObject* item = PyLong_FromLong((long)cvalue[i]);
+          PyObject* item = PyLong_FromLong(static_cast<long>(cvalue[i]));
           PyTuple_SetItem(pyvalue, i, item);
         }
       } else if (k.first == boost::json::kind::int64) {
@@ -148,8 +148,8 @@ static PyObject* pcm_subscript(py_config_map* pycmap, PyObject* pykey)
         pyvalue = PyTuple_New(*cvalue_size);
         // We can use std::views::enumerate once the AppleClang C++ STL supports it.
         for (Py_ssize_t i = 0; i < *cvalue_size; ++i) {
-          PyObject* item =
-            PyUnicode_FromStringAndSize(cvalue[i].c_str(), (Py_ssize_t)cvalue[i].size());
+          PyObject* item = PyUnicode_FromStringAndSize(cvalue[i].c_str(),
+                                                       static_cast<Py_ssize_t>(cvalue[i].size()));
           PyTuple_SetItem(pyvalue, i, item);
         }
       } else if (k.first == boost::json::kind::object) {
@@ -164,8 +164,8 @@ static PyObject* pcm_subscript(py_config_map* pycmap, PyObject* pykey)
         for (Py_ssize_t i = 0; i < *cvalue_size; ++i) {
           PyObject* item = PyDict_New();
           for (auto const& kv : cvalue[i]) {
-            PyObject* val =
-              PyUnicode_FromStringAndSize(kv.second.c_str(), (Py_ssize_t)kv.second.size());
+            PyObject* val = PyUnicode_FromStringAndSize(kv.second.c_str(),
+                                                        static_cast<Py_ssize_t>(kv.second.size()));
             PyDict_SetItemString(item, kv.first.c_str(), val);
             Py_DECREF(val);
           }
@@ -178,7 +178,7 @@ static PyObject* pcm_subscript(py_config_map* pycmap, PyObject* pykey)
     } else {
       if (k.first == boost::json::kind::bool_) {
         auto cvalue = pycmap->ph_config->get<bool>(ckey);
-        pyvalue = PyBool_FromLong((long)cvalue);
+        pyvalue = PyBool_FromLong(static_cast<long>(cvalue));
       } else if (k.first == boost::json::kind::int64) {
         auto cvalue = pycmap->ph_config->get<std::int64_t>(ckey);
         // Note Python3.14 is expected to add PyLong_FromInt64
@@ -192,13 +192,14 @@ static PyObject* pcm_subscript(py_config_map* pycmap, PyObject* pykey)
         pyvalue = PyFloat_FromDouble(cvalue);
       } else if (k.first == boost::json::kind::string) {
         auto const& cvalue = pycmap->ph_config->get<std::string>(ckey);
-        pyvalue = PyUnicode_FromStringAndSize(cvalue.c_str(), (Py_ssize_t)cvalue.size());
+        pyvalue =
+          PyUnicode_FromStringAndSize(cvalue.c_str(), static_cast<Py_ssize_t>(cvalue.size()));
       } else if (k.first == boost::json::kind::object) {
         auto cvalue = pycmap->ph_config->get<std::map<std::string, std::string>>(ckey);
         pyvalue = PyDict_New();
         for (auto const& kv : cvalue) {
-          PyObject* val =
-            PyUnicode_FromStringAndSize(kv.second.c_str(), (Py_ssize_t)kv.second.size());
+          PyObject* val = PyUnicode_FromStringAndSize(kv.second.c_str(),
+                                                      static_cast<Py_ssize_t>(kv.second.size()));
           PyDict_SetItemString(pyvalue, kv.first.c_str(), val);
           Py_DECREF(val);
         }
diff --git a/plugins/python/src/dciwrap.cpp b/plugins/python/src/dciwrap.cpp
index bc75a211c..2baa1bc7f 100644
--- a/plugins/python/src/dciwrap.cpp
+++ b/plugins/python/src/dciwrap.cpp
@@ -27,7 +27,7 @@ PyObject* phlex::experimental::wrap_dci(data_cell_index const& dci)
 // simple forwarding methods
 static PyObject* dci_number(py_data_cell_index* pydci)
 {
-  return PyLong_FromLong((long)pydci->ph_dci->number());
+  return PyLong_FromLong(static_cast<long>(pydci->ph_dci->number()));
 }
 
 // PyMethodDef arrays must be non-const; tp_methods in PyTypeObject takes a non-const pointer.
diff --git a/plugins/python/src/dyncall.cpp b/plugins/python/src/dyncall.cpp
index 5892ddd95..e8a4fe067 100644
--- a/plugins/python/src/dyncall.cpp
+++ b/plugins/python/src/dyncall.cpp
@@ -110,7 +110,7 @@ void phlex::experimental::dyncall(void* fn, dcarg& result, dcargs_t& args, int v
   // because libffi is, and that yields a plethora of warnings from clang-tidy,
   // none of which warrant actual changes.
   // NOLINTBEGIN
-  std::size_t nargs = (std::size_t)args.size();
+  std::size_t nargs = args.size();
 
   auto t = std::make_unique<ffi_type*[]>(nargs);
   auto p = std::make_unique<void*[]>(nargs);
diff --git a/plugins/python/src/modulewrap.cpp b/plugins/python/src/modulewrap.cpp
index e8d33b0d7..c02cf07bc 100644
--- a/plugins/python/src/modulewrap.cpp
+++ b/plugins/python/src/modulewrap.cpp
@@ -177,7 +177,7 @@ namespace {
       PyGILRAII gil;
 
       dcarg result{nullptr};
-      dyncall((void*)m_ccallback, result, argsv, 1);
+      dyncall(m_ccallback, result, argsv, 1);
 
       std::string error_msg;
       if (!result.get<PyObject*>()) {
@@ -227,7 +227,7 @@ namespace {
       argsv.reserve(sizeof...(Is));
       (argsv.push_back(args), ...);
 
-      dyncall((void*)m_ccallback, result, argsv);
+      dyncall(m_ccallback, result, argsv);
       // TODO: error reporting?
 
       if constexpr (!std::is_void_v<RT>) {
@@ -337,7 +337,7 @@ namespace {
     for (Py_ssize_t i = 0; i < len; ++i) {
       PyObject* item = items[i]; // borrowed reference
       if (!PyUnicode_Check(item)) {
-        PyErr_Format(PyExc_TypeError, "item %d must be a string", (int)i);
+        PyErr_Format(PyExc_TypeError, "item %d must be a string", static_cast<int>(i));
         break;
       }
 
@@ -512,9 +512,9 @@ namespace {
     // fail to pass float -> bool; the problem is rounding (0.1 -> 0 -> False)
     if (!(l == 0 || l == 1) || PyFloat_Check(pyobject)) {
       PyErr_SetString(PyExc_ValueError, "boolean value should be bool, or integer 1 or 0");
-      return (bool)-1;
+      return static_cast<bool>(-1);
     }
-    return (bool)l;
+    return static_cast<bool>(l);
   }
 
   long pylong_as_strictlong(PyObject* pyobject)
@@ -535,7 +535,7 @@ namespace {
     }
 
     PyErr_SetString(PyExc_TypeError, "int/long conversion expects a signed integer object");
-    return (long)-1;
+    return static_cast<long>(-1);
   }
 
   unsigned long pylong_or_int_as_ulong(PyObject* pyobject)
@@ -543,7 +543,7 @@ namespace {
     // convert <pybject> to C++ unsigned long, with bounds checking, allow int -> ulong.
     if (PyFloat_Check(pyobject)) {
       PyErr_SetString(PyExc_TypeError, "can\'t convert float to unsigned long");
-      return (unsigned long)-1;
+      return static_cast<unsigned long>(-1);
     }
 
     // accept numpy unsigned integer scalars (uint8, uint16, uint32, uint64)
@@ -557,14 +557,14 @@ namespace {
     }
 
     unsigned long ul = PyLong_AsUnsignedLong(pyobject);
-    if (ul == (unsigned long)-1 && PyErr_Occurred() && PyLong_Check(pyobject)) {
+    if (ul == static_cast<unsigned long>(-1) && PyErr_Occurred() && PyLong_Check(pyobject)) {
       PyErr_Clear();
       long i = PyLong_AS_LONG(pyobject);
       if (0 <= i) {
-        ul = (unsigned long)i;
+        ul = static_cast<unsigned long>(i);
       } else {
         PyErr_SetString(PyExc_ValueError, "can\'t convert negative value to unsigned long");
-        return (unsigned long)-1;
+        return static_cast<unsigned long>(-1);
       }
     }
 
@@ -805,7 +805,7 @@ static PyObject* parse_args(PyObject* args,
   }
 
   // set concurrency, or the default of serial if not set
-  nconcur = nconcur_ > 0 ? (concurrency)nconcur_ : concurrency::serial;
+  nconcur = nconcur_ > 0 ? concurrency(nconcur_) : concurrency::serial;
 
   // retrieve function name
   if (!pyname) {
@@ -1042,7 +1042,7 @@ static PyObject* md_transform(py_phlex_module* mod, PyObject* args, PyObject* kw
   std::vector<std::string> input_types;
   std::vector<std::string> output_suffixes;
   std::vector<std::string> output_types;
-  auto nconcur = (concurrency)-1;
+  concurrency nconcur(-1);
   PyObject* callable = parse_args(
     args, kwds, cname, input_selectors, input_types, output_suffixes, output_types, nconcur);
 
@@ -1190,7 +1190,7 @@ static PyObject* md_observe(py_phlex_module* mod, PyObject* args, PyObject* kwds
   std::vector<std::string> input_types;
   std::vector<std::string> output_suffixes;
   std::vector<std::string> output_types;
-  auto nconcur = (concurrency)-1;
+  concurrency nconcur(-1);
   PyObject* callable = parse_args(
     args, kwds, cname, input_selectors, input_types, output_suffixes, output_types, nconcur);
 
diff --git a/plugins/python/src/pymodule.cpp b/plugins/python/src/pymodule.cpp
index a437cada3..1204d4593 100644
--- a/plugins/python/src/pymodule.cpp
+++ b/plugins/python/src/pymodule.cpp
@@ -210,7 +210,7 @@ static bool initialize()
   // Python interpreter will not happen atm.
   static std::atomic<bool> gil_released{false};
   if (!gil_released.exchange(true)) {
-    (void)PyEval_SaveThread(); // state not saved, as no place to restore
+    PyEval_SaveThread(); // state not saved, as no place to restore
   }
 
   return true;
diff --git a/test/form/form_source_extra_types.cpp b/test/form/form_source_extra_types.cpp
index 195c951b1..326f6f1ec 100644
--- a/test/form/form_source_extra_types.cpp
+++ b/test/form/form_source_extra_types.cpp
@@ -1,6 +1,8 @@
 #include "form/form_source_type_registry.hpp"
 #include "phlex/module.hpp"
 
+#include <utility>
+
 using namespace phlex;
 
 namespace {
@@ -23,9 +25,8 @@ namespace {
   }
 }
 
-PHLEX_REGISTER_ALGORITHMS(m, config)
+PHLEX_REGISTER_ALGORITHMS(m)
 {
-  (void)m;
-  (void)config;
+  std::ignore = m;
   register_extra_form_types_once();
 }
diff --git a/test/product_selecting.cpp b/test/product_selecting.cpp
index 47940b831..efd4f0478 100644
--- a/test/product_selecting.cpp
+++ b/test/product_selecting.cpp
@@ -16,9 +16,12 @@ using namespace std::string_literals;
 
 namespace {
   // Provider functions
-  int provide_idx(data_cell_index const& dci) { return int(dci.number()); }
+  int provide_idx(data_cell_index const& dci) { return static_cast<int>(dci.number()); }
   int provide_number(data_cell_index const&) { return 3; }
-  double provide_temperature(data_cell_index const& dci) { return double(dci.number()) * 100.0; }
+  double provide_temperature(data_cell_index const& dci)
+  {
+    return static_cast<double>(dci.number()) * 100.0;
+  }
   std::string provide_name(data_cell_index const& dci)
   {
     return fmt::format("John the {}th", dci.number());
diff --git a/test/type_distinction.cpp b/test/type_distinction.cpp
index 59d192f2e..0829f8fe0 100644
--- a/test/type_distinction.cpp
+++ b/test/type_distinction.cpp
@@ -24,7 +24,7 @@ namespace {
 
   auto triple(int x) { return 3 * x; }
 
-  auto square(int x) { return std::tuple{x * x, double((x * x) + 0.5)}; }
+  auto square(int x) { return std::tuple{x * x, ((x * x) + 0.5)}; }
 
   int id(int x) { return x; }